Composite bone graft, method of making and using same

ABSTRACT

The invention is directed to a composite bone graft for implantation in a patient, and methods of making and using the composite bone graft, along with methods for treating patients by implanting the composite bone graft at a site in a patient. The composite bone graft includes two or more connected, discrete, bone portions, and includes one or more biocompatible connectors which hold together the discrete bone portions to form the composite bone graft. The composite bone graft may include one or more textured bone surfaces. The textured surface preferably includes a plurality of closely spaced protrusions, preferably closely spaced continuous protrusions. The composite bone graft is useful for repairing bone defects caused by congenital anomaly, disease, or trauma, in a patient, for example, for restoring vertical support of the anterior and/or posterior column. Implantation of the composite bone graft results in improved graft stability and osteoinductivity, without a decrease in mechanical strength. The composite bone graft does not shift, extrude or rotate, after implantation. The present composite bone graft can be appropriately sized for any application and can be used to replace traditional non-bone prosthetic implants.

This application is a Continuation-in-Part application of U.S. patentapplication Ser. No.: 09/286,975, filed Apr. 6, 1999 now abandoned,which is a Continuation-in-Part of U.S. patent application Ser. No.:09/225,299, now abandoned filed Jan. 5, 1999, now abandoned, which is aContinuation-in-Part of application Ser. No. 09/368,263, filed Aug. 3,1999, now U.S. Pat. No. 6,200,347.

FIELD OF THE INVENTION

The invention relates to bone grafts and more particularly, to bonegrafts useful for spinal fusion. The invention provides a composite bonegraft for implantation in a patient, and methods of making and using thecomposite bone graft. The composite bone graft contains two or moredistinct bone portions where the bone portions are connected. The boneportions are preferably self-locking, interlocking, and/or connected byat least one mechanical connector, including for example, a bone pin.One or more of the bone portions may be demineralized, and may also becontinuous or discontinuous. The composite bone graft may include one ormore textured surfaces, preferably including a plurality of closelyspaced protrusions. The composite bone graft is useful for repairingbone defects caused by congenital anomaly, disease, or trauma, and isparticularly useful for spinal fusions. The composite bone graft can beappropriately sized for any application and can be used to replacetraditional non-bone prosthetic implants. The composite bone graftpromotes the growth of patient bone at an implantation site by promotingosteoinductivity and cellularization, provides added stability andmechanical strength, and does not shift, extrude or rotate, afterimplantation.

BACKGROUND OF THE INVENTION

In the field of prosthetic implants, materials often used include bonegrafts and implants produced from non-bone materials, including forexample stainless steel, titanium and plastics. The choice of whether touse a bone or a non-bone implant often depends on the clinicalindication, implant site, whether the implant is load-bearing, and thesize of the implant needed.

Prior to the present invention, the use of bone grafts versus non-boneprosthetic implants to for example, support and fuse together adjacentvertebrae, has been limited in part by the physical size of a corticalbone graft. Interbody bone grafting involves the problem of strength.Strong cortical bone (the outer layer) is required as a strut in theinterbody position to prevent collapse of the disc space while healingoccurs. For example, cortical bone obtained from a cadaver sourcefashioned into struts, is not wide enough for optimum load bearing. Thisnatural limitation often excludes the use of a bone graft product.

The success or failure of a bone graft further depends on whether thebone graft remains at the implant site, is cellularized, and whether itcan withstand the mechanical load. In spinal surgery, there are twoprimary indications for use of allograft bone: (1) when there isinsufficient available autograft bone, and (2) in spinal fusionprocedures when a structural element in needed. Typically, bone graftsare affixed at an implant site by fusion. Bone grafts for spinalapplications often fail because they are extruded from the implantationsite due to shifting, rotation, and slippage of the graft, are notcellularized, or fail mechanically.

The invention enables the use of bone grafts for applications normallysuited for only non-bone prosthetic implants. The invention solves theproblem of graft failure by providing a composite bone graft which canbe appropriately sized for any application out of for example, strongcortical bone; promotes the ingrowth of patient bone at an implantationsite by promoting osteoinductivity and cellularization; provides addedstability and mechanical strength; and does not shift, extrude orrotate; after implantation.

SUMMARY OF THE INVENTION

The present invention is directed to a composite bone graft forrepairing bone defects caused by congenital anomaly, disease, or trauma,including for example, for restoring vertical support of the posteriorand/or anterior column. The present composite bone grafts can be used asstructural grafts placed posteriorly in the spine as interbody grafts oras strut grafts spanning multiple segments. Posterior composite bonegrafts can be used to supplement autologous bone for spinal fusions inpatients who lack sufficient host bone and to avoid significant donorsite morbidity. The present composite bone grafts can be used forapplications normally suited for only non-bone prosthetic implantsbecause the composite bone graft can be appropriately sized for anyapplication and has adequate mechanical strength.

The invention provides a composite bone graft including a plurality ofbone portions layered to form a graft unit, and one or morebiocompatible connectors for holding together the graft unit.

The invention also provides a composite bone graft including two or moredistinct bone portions, and one or more biocompatible connectors, wherethe biocompatible connectors hold together the two or more bone portionsto form the composite bone graft.

The present invention provides a composite bone graft including two ormore connected, distinct bone portions.

The present invention provides a composite bone graft including three ormore connected, distinct bone portions.

The present invention provides a composite bone graft including three ormore connected, distinct cortical bone portions.

The present invention provides a composite bone graft including one ormore horizontally disposed channels provided through the composite bonegraft perpendicular to the interfaces of the bone portions.

The present invention also provides a composite bone graft including oneor more vertically disposed channels provided through the composite bonegraft parallel to the interfaces of the bone portions.

The present invention further provides a composite bone graft includingone or more horizontally disposed channels and vertically disposedchannels where the one or more channels includes one or moretherapeutically beneficial substances.

The invention further provides a composite bone graft including two ormore connected bone portions, where the bone portions can includecortical bone and cancellous bone.

The invention also provides a composite bone graft, including a firstbone portion, a second bone portion, a third bone portion, the first,second and third bone portions are disposed one on the other (ie.layered) to form a graft unit; and one or more biocompatible connectorsfor holding together the graft unit.

The invention provides a composite bone graft, including a firstcortical bone portion, a second cortical bone portion, a cancellous boneportion disposed between the first cortical bone portion and the secondcortical bone portion to form a graft unit, and one or morebiocompatible connectors for holding together the graft unit.

The invention further provides a composite bone graft, including a firstcortical bone portion, a second cortical bone portion provided on thefirst cortical bone portion to form a graft unit; and one or morebiocompatible connectors for holding together the graft unit.

The invention provides a composite bone graft, including a plurality oflayered cortical bone portions forming a graft unit, and one or morebiocompatible connectors for holding together the graft unit.

The invention provides a composite bone graft, including a plurality oflayered bone portions forming a graft unit, and one or morebiocompatible connectors for holding together the graft unit.

The invention also provides a composite bone graft, including a firstbone portion, a second bone portion provided on the first bone portionto form a graft unit, and one or more biocompatible connectors forholding together the graft unit.

The invention provides a composite bone graft including a plurality ofdistinct bone portions, where one or more of the bone portions aredemineralized.

The invention provides a composite bone graft including a plurality ofdistinct bone portions, where one or more of the bone portions arecontinuous or discontinuous.

The invention further provides a composite bone graft including aplurality of distinct bone portions where one or more of the boneportions include a discontinuous bone portion, the as discontinuous boneportion including one or more therapeutically beneficial substancesincluding but not limited to, for example, one or more of the following:osteoinductive substances, osteoconductive substances, andpharmaceutically active agents. Such therapeutically beneficialsubstances may optionally be provided with a carrier. Suitableosteoinductive substances include but are not limited to, for example,autograft bone; allograft bone; Grafton™ produced by Osteotech;DynaGraft™; demineralized cortical bone; demineralized cancellous bone;collagen including one or more growth factors including for exampleNovus™ produced by Stryker Biotech; collagen including demineralizedbone including for example DynaGraft™; cancellous bone; cortical bone;OpteoForm™ produced by the University of Florida; OsteoFill™ produced bythe University of Florida; and growth factors including for example,bone morphogenic protein, and transforming growth factor-β. Suitableosteoconductive substances include but are not limited to, for example,hydroxyapitate; collagen; any biocompatible matrix material includingfor example, polymeric matrix materials, bioglass, bioceramics,resorbable Biomaterials; bioabsorbable polymers; a plastic matrix;stainless steel; titanium; cobalt-chromium-molybdenum alloy matrix; andsubstances including hydroxyapitate, including for example, Osteoset™produced by Wright Medical. Suitable pharmaceutically active agentsinclude but are not limited to, for example, growth factors includingfor example bone growth factors including for example bone morphogenicprotein, and transforming growth factor-β, chemotherapeutic agents,anti-inflammatory agents, and antibiotics.

The invention also provides a composite bone graft, including a firstcortical bone portion, a second cortical bone portion, a cancellous boneportion disposed between the first cortical bone portion and the secondcortical bone portion to form a graft unit, and one or morebiocompatible connectors for holding together the graft unit, where thecancellous bone portion is demineralized and discontinuous.

The invention provides a composite bone graft, including a firstcortical bone portion, a second cortical bone portion, and a thirdcortical bone portion disposed between the first cortical bone portionand the second cortical bone portion to form a graft unit, and one ormore biocompatible connectors for holding together the graft unit, wherethe third cortical bone portion is demineralized and discontinuous.

The invention provides a composite bone graft, including a firstcortical bone portion, and a second cortical bone portion disposed apartfrom each other, and forming a graft unit, and one or more biocompatiblemechanical connectors for holding together the graft unit, where thefirst and second cortical bone portions are disposed separate from eachother by the biocompatible mechanical connectors, thereby forming asubstantially void central area.

The invention further provides a composite bone graft including asubstantially void central area, where the substantially void centralarea further includes one or more therapeutically beneficial substancesincluding but not limited to, for example, one or more of the following:osteoinductive substances, osteoconductive substances, andpharmaceutically active agents. Such therapeutically beneficialsubstances may optionally be provided with a carrier. Suitableosteoinductive substances include but are not limited to, for example,autograft bone; allograft bone; Grafton™ produced by Osteotech;DynaGraft™; demineralized cortical bone; demineralized cancellous bone;collagen including one or more growth factors including for exampleNovus™ produced by Stryker Biotech; collagen including demineralizedbone including for example DynaGraft™; cancellous bone; cortical bone;OpteoForm™ produced by the University of Florida; OsteoFill™ produced bythe University of Florida; and growth factors including for example bonemorphogenic protein, and transforming growth factor-β. Suitableosteoconductive substances include but are not limited to, for example,hydroxyapitate; collagen; any biocompatible matrix material includingfor example, polymeric matrix materials, bioglass, bioceramics,resorbable Biomaterials; bioabsorbable polymers; a plastic matrix;stainless steel; titanium; cobalt-chromium-molybdenum alloy matrix; andsubstances including hydroxyapitate, including for example, Osteoset™produced by Wright Medical. Suitable pharmaceutically active agentsinclude but are not limited to, for example, growth factors includingfor example bone growth factors including for example bone morphogenicprotein, and transforming growth factor-β; chemotherapeutic agents;anti-inflammatory agents; and antibiotics. The material may be in anysuitable form including for example, in the form of a solid, sponge,paste, powder, and/or gel.

The invention further provides a composite bone graft where thebiocompatible connectors include one or more mechanical biocompatibleconnectors.

The invention provides a composite bone graft where the biocompatibleconnectors include a chemical biocompatible connector.

The invention further provides a composite bone graft where themechanical biocompatible connectors include one or more pins.

The invention further provides a composite bone graft where the chemicalbiocompatible connectors include a biocompatible adhesive.

The invention provides a composite bone graft where one or morebiocompatible connectors include one or more of the following: amechanical connector and a chemical connector.

The invention also provides a composite bone graft where the mechanicalbiocompatible connectors include one or more of the followingbiocompatible materials: cortical bone; stainless steel; titanium;cobalt-chromium-molybdenum alloy; a bioceramic; a bioglass; a plastic ofone or more of the following: nylon, polycarbonate, polypropylene,polyacetal, polyethylene, and polysulfone; and one or more bioabsorbablepolymers.

The invention also provides a composite bone graft where the mechanicalbiocompatible connectors include cortical bone.

The invention provides a composite bone graft where the one or more pinsinclude one or more cortical bone pins.

The invention provides a composite bone graft where the graft unitincludes one or more through-holes configured to accomadate the one ormore pins.

The invention further provides a composite bone graft where thethrough-holes are disposed perpendicular to interfaces of bone portionsforming the graft unit.

The invention further provides a composite bone graft where thethrough-holes are disposed perpendicular to interfaces of for example,the first bone portion, the second bone portion, and the third boneportion, of the graft unit.

The invention provides a composite bone graft where the one or more pinsand the one or more through-holes are configured to provide aninterference fit for holding together the graft unit.

The invention also provides a composite bone graft where the one or morethrough-holes and the one or more pins are round and an inner diameterof a through-hole is smaller than a diameter of a pin, to provide aninterference fit between the through-hole and the pin.

The invention further provides a composite bone graft where the one ormore cortical bone pins include a plurality of vertical groves providedon a surface thereof.

The invention further provides a composite bone graft where the one ormore cortical bone pins includes a roughened surface.

The invention provides a composite bone graft where the one or morecortical bone pins further includes a slot extending from one end of thebone pin.

The invention provides a composite bone graft where the one or more pinsis threaded to provide a threaded engagement with the one or morethrough-holes.

The invention further provides a composite bone graft where the one ormore pins is threaded and the one or more through-holes is threaded, toprovide a threaded engagement between the one or more pins and the oneor more through-holes.

The invention provides a composite bone graft where the one or more pinsand the one or more through-holes are configured to provide a slidableconnection, for example, to provide a composite bone graft including asubstantially void central area.

The invention also provides a composite bone graft where a cross-sectionof the one or more pins includes a shape selected from the groupincluding the following: round, ovoid, square, rectangular, triangular,pentagon, hexagon, and trapezoidal.

The invention further provides a composite bone graft including aplurality of plate-like cortical bone portions, the cortical boneportions layered to form a graft unit, the graft unit held together withone or more cortical bone pins.

The invention further provides a composite bone graft where thecomposite bone graft is a cortical cylinder.

The invention provides a composite bone graft including a graft unithaving one or more through-holes configured to accommadate one or morepins, the graft unit including two or more bone portions layered to formthe graft unit, and one or more pins for holding together the graftunit.

The invention further provides a composite bone graft, including a graftunit having one or more through-holes configured to accommadate one ormore pins, the graft unit including a first plate-like cortical bone, asecond plate-like cortical bone, a plate-like cancellous bone disposedbetween the first plate-like cortical bone and the second plate-likecortical bone to form the graft unit, and one or more cortical bone pinsfor holding together the graft unit.

The invention also provides a composite bone graft, including a graftunit having one or more through-holes configured to accomadate one ormore pins, the graft unit including a first plate-like bone, a secondplate-like bone provided on the first plate-like bone to form the graftunit, and one or more bone pins for holding together the graft unit.

The invention also provides a cervical composite bone graft, including aflattened curved wedge graft unit having one or more through-holesconfigured to accomadate one or more pins, the graft unit including twoor more plate-like cortical bone portions layered to form the graftunit, and at least two bone pins for holding together the graft unit,where the graft unit includes a substantially centrally locatedthrough-hole. The diameter of the through-hole may be readily selectedby one of ordinary skill in the art without undue experimentationdepending upon the particular application; for example, the diameter ofthe through-hole may be from about 2.0 mm-4.0 mm; preferably 2.5 mm-3.0mm; and more preferably 3.0 mm.

The invention also provides a composite bone graft where the one or morethrough-holes are disposed perpendicular to interfaces of plate-likebones of the graft unit.

The invention provides a composite bone graft where the composite bonegraft is a parallelepiped; a parallel block; a square block; a trapezoidwedge; a cylinder; a tapered cylinder; a cervical wedge (flattenedcurved wedge); an ovoid wedge (anterior lumbar wedge graft) and apolyhedron.

The invention further provides a composite bone graft where thecomposite bone graft is a polyhedron including six planer surfaces.

The invention provides a composite bone graft where the composite bonegraft further includes one or more textured surfaces.

The invention also provides a composite bone graft where the one or moretextured surfaces includes a plurality of closely spaced continuousprotrusions.

The invention provides a composite bone graft where the continuousprotrusions include a cross-section having one or more shapes selectedfrom the following: irregular; triangular, square, rectangular, andcurved.

The invention further provides a composite bone graft where theplurality of continuous protrusions are sized to be in a range ofgreater than or equal to about 1.5 mm in length; 0.5 to about 10.0 mm inwidth and 0.1 to about 5.0 mm in depth.

The invention provides a composite bone graft where the plurality ofclosely spaced continuous protrusions are spaced from about 0.0 to about3.0 mm apart.

The invention provides a composite bone graft where the plurality ofprotrusions are spaced from about 0.1 to about 2.0 mm apart.

The invention also provides a composite bone graft where the pluralityof protrusions are spaced about 0.5 mm apart.

The invention provides a method for restoring vertical support of theposterior and/or anterior column by implanting a composite bone graftincluding two or more distinct bone portions held together by one ormore connectors, at a site in a patient.

The invention provides a composite bone graft containing two or moreconnected bone portions, where the composite bone graft has a pluralityof closely spaced protrusions on one or more surfaces thereof, where theprotrusions are continuous protrusions, discrete protrusions, or acombination thereof.

The invention provides a composite bone graft where the plate-likecortical and/or cancellous bone portions are continuous bone portionsand/or discontinuous bone portions.

The invention provides a composite bone graft including one or morediscontinuous bone portions.

The invention provides a composite bone graft including one or morediscontinuous, demineralized cortical bone portions.

The invention provides a composite bone graft including one or morediscontinuous, demineralized cancellous bone portions.

The invention further provides a composite bone graft where one or morecontinuous or discontinuous cancellous bone portions, (continuous ordiscontinuous and/or demineralized)includes one or more therapeuticallybeneficial substances including but not limited to, for example, one ormore of the following: osteoinductive substances, osteoconductivesubstances, and pharmaceutically active agents. Such therapeuticallybeneficial substances may optionally be provided with a carrier.Suitable osteoinductive substances include but are not limited to, forexample, autograft bone; allograft bone; Grafton™ produced by Osteotech;DynaGraft™; demineralized cortical bone; demineralized cancellous bone;collagen including one or more growth factors including for exampleNovus™ produced by Stryker Biotech; collagen including demineralizedbone including for example DynaGraft™; cancellous bone; cortical bone;OpteoForm™ produced by the University of Florida; OsteoFill™ produced bythe University of Florida; and growth factors including for example bonemorphogenic protein, and transforming growth factor-β. Suitableosteoconductive substances include but are not limited to, for example,hydroxyapitate; collagen; any biocompatible matrix material includingfor example, polymeric matrix materials, bioglass, bioceramics,resorbable Biomaterials; bioabsorbable polymers; a plastic matrix;stainless steel; titanium; cobalt-chromium-molybdenum alloy matrix; andsubstances including hydroxyapitate, including for example, Osteoset™produced by Wright Medical. Suitable pharmaceutically active agentsinclude but are not limited to, for example, growth factors includingfor example bone growth factors including for example bone morphogenicprotein, and transforming growth factors; chemotherapeutic agents;anti-inflammatory agents; and antibiotics.

The invention provides a composite bone graft where one or morecontinuous or discontinuous cancellous bone portions are demineralizedand include one or more therapeutically beneficial substances.

The invention provides a composite bone graft where one or morediscontinuous cortical bone portions, include one or moretherapeutically beneficial substances.

The invention further provides a composite bone graft where one or morediscontinuous cortical bone portions are demineralized and include oneor more therapeutically beneficial substances.

The invention also provides a composite bone graft including a two ormore distinct bone portions held together by one or more connectors,where the composite bone graft includes two diametrically opposingchamfered edges, one provided along the length of the graft at its topedge and the other provided along the length of the graft at its bottomedge, such that the chamfered edges are diametrically opposing.

The invention further provides a composite bone graft including two ormore distinct interlocking cortical bone portions.

The invention provides a composite bone graft including two or moredistinct interlocking bone portions, where the interlocking boneportions are self-locking.

The invention also provides a composite bone graft including two or moredistinct interlocking bone portions, where the interlocking boneportions are locked with one or more locking pins.

The invention further provides a composite bone graft where boneportions are locked with one or more locking pins entirely or partiallytraversing a dimension of the composite bone graft.

The invention provides an interlocking composite bone graft where eachcomplementary bone portion is provided with a discrete or continuousinterlocking pattern.

The invention also provides an interlocking composite bone graftincluding two or more distinct adjacent bone portions where adjacentbone portions are configured to interlock with each other, and one ormore bone pins partially or entirely traversing a dimension of thegraft, where the dimension of the graft is the length, width, or heightof the graft.

The invention provides an interlocking composite bone graft includingtwo or more distinct adjacent bone portions where adjacent bone portionsare configured to interlock with each other.

The invention provides a composite bone graft including two or moredistinct adjacent interlocking bone portions where adjacent boneportions include complementary peg-like protrusions and correspondingdepressions, such that the protrusions and depressions provide aninterlocking fit between the bone portions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. FIG. 1 illustrates a perspective view of a trapezoid wedgecomposite bone graft having a non-textured surface.

FIG. 2. FIG. 2 illustrates a side view of a trapezoid wedge compositebone graft having opposing textured surfaces provided perpendicular tothe interfaces of the bone portions. The textured surfaces illustratecontinuous linear protrusions defining a saw-tooth-like pattern.

FIG. 3. FIG. 3 illustrates a cross-section posterior view of thetrapezoid wedge composite bone graft of FIG. 2.

FIG. 4. FIG. 4 illustrates a cross-section anterior view of thetrapezoid wedge composite bone graft of FIG. 2.

FIG. 5. FIG. 5 illustrates a top view of the trapezoid wedge compositebone graft of FIG. 2, and having a textured surface.

FIG. 6. FIG. 6 is a perspective view of the trapezoid wedge compositebone graft of FIG. 2, and having a textured surface.

FIG. 7. FIG. 7 illustrates a perspective of a preferred slidablyconnected composite bone graft having a first cortical bone portion, asecond cortical bone portion, cortical bone pins, through-holes, and acentrally located void.

FIG. 8. FIG. 8 illustrates a top view of the slidably connectedcomposite bone graft of FIG. 7, having a first cortical bone portion, asecond cortical bone portion, and a cancellous bone portion disposedthere between.

FIG. 9. FIG. 9 illustrates a perspective view of a preferred embodimentof the composite bone graft.

FIG. 10. FIG. 10 illustrates a preferred cortical dowel composite bonegraft including a plurality of cortical bone portions connected by asingle cortical bone pin inserted into a through-hole.

FIG. 11A. FIG. 11A illustrates the method of making a preferredembodiment of the composite bone graft.

FIG. 11B. FIG. 11B illustrates a method for producing bone pins andproducing a pinned graft unit.

FIG. 12. FIG. 12 illustrates another method for making a composite bonegraft.

FIGS. 13A & 13B. FIG. 13A is a perspective view of a preferred trapezoidblock composite bone graft having opposing textured surfaces; FIG. 13Bis a detail of the protrusions of the textured surface.

FIGS. 14A, 14B & 14C. FIGS. 14A, 14B and 14C, illustrate a cervicalwedge (flattened curved wedge) composite bone graft for use in cervicalfusions where 14A is a perspective standing view, 14B is a side view,and 14C is a perspective view where the graft is provided with opposingtextured surfaces.

FIG. 15. FIG. 15 illustrates a method for making a cervical wedgecomposite bone graft for use in cervical fusions.

FIG. 16. FIG. 16 illustrates a perspective view of a mechanical pinconnector having a slot extending from its lower end.

FIG. 17. FIG. 17 illustrates a side view of the mechanical pin connectorof FIG. 16, having a slot extending from its lower end.

FIG. 18. FIG. 18 illustrates a cross-section view of the mechanical pinconnector of

FIG. 16, having a slot extending from its lower end.

FIG. 19. FIG. 19 illustrates a perspective view of a mechanical pinconnector having a plurality of horizontally disposed grooves.

FIG. 20. FIG. 20 illustrates a perspective view of a mechanical pinconnector having helical threads.

FIG. 21. FIG. 21 illustrates a perspective view of a mechanical pinconnector having a plurality of vertically disposed grooves.

FIG. 22. FIG. 22 illustrates a perspective view of a mechanical slottedpin connector.

FIG. 23 FIG. 23 illustrates a perspective view of a mechanical pinconnector having plurality of horizontally disposed ridges.

FIG. 24. FIG. 24 illustrates a perspective view of a mechanicaltriangular pin connector.

FIG. 25. FIG. 25 illustrates a perspective view of a mechanical squarepin connector

FIG. 26. FIG. 26 illustrates a perspective view of a mechanical hexagonpin connector.

FIG. 27. FIG. 27 illustrates a perspective view of a rectangular blockcomposite bone graft having a demineralized cortical bone portionsandwiched between two cortical bone portions, where the demineralizedcortical bone portion is provided with perforations and channels, andwhere the composite graft includes opposing textured surfaces providedperpendicular to the interfaces of the bone portions. The texturedsurfaces illustrate continuous linear protrusions defining asaw-tooth-like pattern.

FIG. 28. FIG. 28 illustrates a perspective view of a rectangular blockcomposite bone graft having a demineralized cancellous bone portionsandwiched between two cortical bone portions, where the composite graftincludes opposing textured surfaces provided perpendicular to theinterfaces of the bone portions. The textured surfaces illustratecontinuous linear protrusions defining a saw-tooth-like pattern.

FIG. 29. FIG. 29 illustrates a preferred method of making the bone graftof FIG. 27.

FIG. 30. FIG. 30 illustrates a preferred method of making the bone graftof FIG. 28.

FIG. 31A. FIG. 31A illustrates a top view of a composite bone graftincluding a void disposed between two cortical bone portions where thevoid includes one or more therapeutically beneficial substances. FIG.31B illustrates a perspective view of a composite bone graft including avoid disposed between two cortical bone portions where the void includesone or more therapeutically beneficial substances, and the compositegraft includes opposing textured surfaces.

FIGS. 32A, 32B, & 32C FIGS. 32A, 32B, and 32C, illustrate a top view, across-section, and a side view, respectively, of a preferred parallelblock composite bone graft.

FIGS. 33A, 33B, & 33C. FIGS. 33A, 33B, and 33C, illustrate a top view, across-section, and a side view, respectively, of a preferred trapezoidwedge composite bone graft.

FIG. 34. FIG. 34 illustrates a perspective view of a preferred trapezoidwedge composite bone graft having opposing textured surfaces and havinga horizontally disposed channel and vertically disposed canals.

FIGS. 35A & 35B. FIG. 35A illustrates a standing view of a preferredcervical wedge composite bone graft for use in cervical fusions, havinghorizontally disposed channels and having a centrally locatedthrough-hole including an osteoconductive substance. FIG. 35Billustrates a side view of the cervical wedge graft of FIG. 35Aincluding a vertically disposed channel.

FIGS. 36A, 36B, & 36C. FIGS. 36A, 36B, and 36C, illustrate across-section, a top view, and a side view, respectively, of a preferredtrapezoid wedge composite bone graft.

FIG. 37. FIG. 37 illustrates a standing view of a cervical wedge(flattened curved wedge)composite bone graft for use in cervicalfusions.

FIG. 38. FIG. 38 illustrates a standing view of a cervical wedge(flattened curved wedge)composite bone graft for use in cervicalfusions.

FIG. 39. FIG. 39 illustrates a perspective view of a preferredembodiment of the composite bone graft including two interlockingcortical bone portions.

FIGS. 40A & 40B. FIG. 40A illustrates a side view of a preferredembodiment of a cervical wedge composite bone graft including twointerlocking cortical bone portions, and FIG. 40B illustrates aperspective view of the graft including two interlocking cortical boneportions.

FIG. 41. FIG. 41 illustrates a perspective view of a preferred trapezoidwedge bone graft including three interlocking cortical bone portions.

FIGS. 42A, 42B, & 42C. FIGS. 42A, 42B, & 42C illustrate side views ofpreferred composite bone grafts including two interlocking cortical boneportions where the interlocking interface defines a sawtooth pattern, astepped pattern and a lock & key pattern, respectively.

FIG. 43. FIG. 43 illustrates a standing view of a cervical wedge(flattened curved wedge)composite bone graft for use in cervicalfusions.

FIG. 44. FIG. 44 illustrates a standing view of a cervical wedge(flattened curved wedge)composite bone graft for use in cervicalfusions.

FIG. 45. FIG. 45 illustrates a cross-section view of a preferred boneimplant including two cortical bone portions having a single depressionprovided on one portion and a corresponding depression provided on theother bone portion to provide an interlock between the bone portions anda cortical bone pin provided parallel to the interface of the boneportions, partially traversing the bone graft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Definitions

The below definitions serve to provide a clear and consistentunderstanding of the specification and claims, including the scope to begiven such terms.

Bioabsorbable polymers. By the term “bioabsorbable polymers” is intendedfor the purposes of the present invention, bioresorbable, bioabsorbable,biodegradable, and bioerodible materials that are well known to those ofordinary skill in the art and are described in Biomaterials Science-AnIntroduction to Materials in Medicine, edited by Ratner, B. D. et al.,Academic Press, (1996), and include for example, the followingmaterials: chitosan; isomorphic ploy(hexamethyleneco-trans-1,4-cyclohexane dimethylene oxalates); poly(glycolic acid);copolymers of poly(glycolic acid) and poly(lactic acid); polydioxanone;poly(latic acid); polymers having a back-bone structure selected fromthe group consisting of: polyanhydrides, polyphophazenes,polyphosphonates, polyamides, and polyiminocarbonates;polyhydroxybutyrate; polyhydroxyvalerate; copolymers ofpolyhydroxybutyrate and polyhydroxyvalerate; polycaprolactone;polydioxanone; poly(γ-ethyl glutamate); poly (DTH iminocarbonate);poly(Bisphenol A iminocarbonate); poly(DETOSU-1,6 HD-t-CDM ortho ester);poly(Sebacic acid-hexadecandioic acid anhydride); poly(ortho esters);poly(amino acids); and PLOA. Such polymers may optionally include one ormore pharmaceutically active agents for controlled release applications,such agents including for example: osteoinductive factors including forexample bone morphogenic protein; growth factors including for exampletransforming growth factor-β; chemotherapeutic agents; antiobiotics; andanti-inflammatory agents.

Biocompatible. By the term “biocompatible” is intended for the purposesof the present invention; any material which when implanted in a patientdoes not provoke an adverse response in the patient. A suitablebiocompatible material when introduced into a patient is not toxic orinjurious to that patient, or does not cause immunological rejection.

Biomechanical strength. By the term “biomechanical strength” is intendedfor the purposes of the present invention, those properties exhibited bya bone graft, including loading strength, compressive strength, andtensile strength.

Bone. By the term “bone” is intended for the purposes of the presentinvention, bone recovered from any source including animal and human,for example, human bone recovered for the production of allografts, andanimal bone recovered for the production of xenografts, such allograftsand xenografts suitable for implantation into a human. Such boneincludes: any bone or portion thereof, including cut pieces of bone,including cortical and/or cancellous bone, for example, recovered from ahuman including a living human or a cadaver, or animal, and processedfor implantation into a living patient. Such bones including forexample: the humorous, hemi-pelvi, tibia, fibula, radius, ulna, rib,vertebrae, mandibular, femur, and, ilia, and any cut portion thereof.Such bone may be demineralized or not demineralized. In a preferredembodiment a cancellous or cortical bone section is demineralized anddisposed between two non-demineralized cortical bone portions. Suitablebone may also include continuous or discontinuous bone portions. Forexample, one or more bone portions of a composite bone graft may bediscontinuous, for example, a bone portion may be perforated anddemineralized, for example perforated either before or afterdemineralization, for example, to allow for uniform demineralization(perforations before demineralization) and to promote ingrowth ofpatient bone. Cancellous and/or demineralized cancellous and/ordiscontinuous cancellous and/or demineralized discontinuous cancellousand or discontinuous cortical and/or demineralized discontinuouscortical, bone, may optionally include one or more therapeuticallybeneficial substances provided with or without a carrier. transforminggrowth factor-β; The composite bone graft may include a substantiallyvoid central area, where the substantially void central area furtherincludes one or more therapeutically beneficial substances provided withor without a carrier. The material maybe in any suitable form includingfor example, in the form of a solid, sponge, paste and/or gel.

Bone marrow elements. By the term “bone marrow elements” is intended forthe purposes of the present invention, the highly cellular hematopoieticconnective tissue filling the medullary cavities and spongy epiphysis ofbones which may harbor bacterial and/or viral particles and/or fungalparticles, and includes for example, blood and lipid.

Chamfer. By the term “chamfer” is intended for the purposes of theinvention, an oblique face formed at a corner of a composite bone graft,at an angle to the adjacent principal faces. Suitable angles includeangles in the range of from 38° to 52°, more preferably 40° to 50°, evenmore preferably 42° to 48°, and most preferably about 45°.

Cleaned bone. By the term “cleaned bone” is intended for the purposes ofthe present invention, a bone or cut portion thereof, that has beenprocessed using means known in the art, to remove bone marrow elements.

Closely Spaced. By the term “closely spaced” is intended for thepurposes of the present invention, protrusions (discrete or continuous)which are in close proximity to each other. Preferably the protrusionsare spaced no more than 3.0 mm apart (i.e. the distance between theedges of two adjacent protrusions), more preferably no more than 2.0 mmapart, even more preferably no more than 1.5 mm apart, and mostpreferably about 0.5 mm apart

Composite. By the term “composite” is intended for the purposes of thepresent invention, a bone graft which is made up of two or more distinctbone portions.

Connector. By the term “connector” is intended for the purposes of thepresent invention, a means of connecting two or more distinct boneportions, including for example a chemical and/or mechanical means. Bythe term “mechanical connector” is intended for the purposes of thepresent invention, a structural member including for example, a pin. Bythe term “chemical connector” is intended for the purposes of thepresent invention, a biocompatible composition including for example,one or more biocompatible adhesives and one or more surface modificationagents and methods.

Continuous Bone Portion. By the term “continuous bone portion” isintended for the purposes of the present invention, a bone portion thatis substantially solid without any artificial void areas.

Continuous Protrusion. By the term “continuous protrusion” is intendedfor the purposes of the present invention, a protrusion whose lengthcontinues substantially uninterrupted, including for example a linear orcurved protrusion whose length is at least three times greater than itswidth, preferably at least five times greater, and includes for examplea continuous, protruding concentric ring, and a continuous linearprotrusion, for example, as illustrated in FIG. 2. Each continuousprotrusion may or may not be distinct from another continuousprotrusion.

Demineralized Bone. By the term “demineralized bone” is intended for thepurposes of this invention, one or more distinct bone portions whichhave been demineralized by any method well known to those of ordinaryskill in the art. Cortical bone is preferably demineralized in 0.5 to0.6 N hydrochloric acid for a period of time of from about 1 to about 8hours, more preferably for a time period of about two hours, at 25° C.to 50° C., more preferably at 25° C. to 37° C. Cancellous bone ispreferably demineralized in 0.5 to 0.6N hydrochloric acid for a periodof time of from about 20 minutes to about 6.0 hours, more preferably fora time period of from about 30 minutes to about 2.0 hours. Preferably,cortical and/or cancellous bone is demineralized to contain less than 10wt % residual calcium, more preferably about less than 5 wt % residualcalcium, even more preferably about 1 wt % to about 3 wt %, and mostpreferably about 2 wt % residual calcium. Other methods fordemineralizing bone are well known in the art to which the presentinvention pertains, and can be readily selected and employed by one ofordinary skill in the art, without undue experimentation.

Discontinuous Bone Portion. By the term “discontinuous bone portion” isintended for the purposes of the present invention, a bone portion thatcontains artificially created void areas including for example, aperforated bone portion, where the perforations or channels may be ofany shape and may partially or completely transverse the bone portion.Such perforations may be randomly disposed or disposed in a regularpattern on and/or through the bone portion. Suitable perforationsinclude perforations traversing the width of the bone portion providedperpendicular to the interfaces of the bone portions of the compositegraft, and channels traversing the height of the bone portion providedparallel to the interfaces of the bone portions of the composite graft.Such perforations allow for uniform demineralization of a bone portion,and allow for ingrowth of patient bone. A demineralized discontinuousbone portion may be perforated prior to demineralization or afterdemineralization.

Discrete Protrusion. By the term “discrete protrusion” is intended forthe purposes of the present invention, a protrusion which isdiscontinuous, i.e. which has a distinct length and width, where eachdiscrete protrusion is separate and distinct from every other discreteprotrusion, and includes for example a protrusion whose length is lessthan three times its width, preferably less than twice its width andmore preferably a protrusion whose length is about equal to its width.

Interlocking. By the term “interlocking” is intended for the purposes ofthe present invention, any pattern provided on a bone portion whichallows that bone portion to engage or interlace with another boneportion, such that the engaged bone portions act as a single boneportion when stressed. Such bone portions may be provided with engagingpatterns including but not limited to the following: step patterns,sawtooth patterns, and ridged patterns, patterns that define mortise andtenon joints, and lock and key type patterns. These patterns may beeither discrete, for example one bone portion may include one or moreprotrusions and a complementary bone portion may be provided with one ormore corresponding depressions, or continuous, for example bone portionsare provided with complementary continuous groove (See FIGS. 39, 40, and41). The discrete patterns, may include protrusions and correspondingdepressions of any shape and size sufficient to provide an interlockingfit, and include round, square, rectangular, triangular, oval,irregular, and any combination of geometric and curved shapedprotrusions and corresponding depressions. The depth/height of thediscrete or continuous patterns is from about 0.1 mm to about 3.5 mm,preferably from about 0.2 mm to about 2.0 mm, more preferably from about0.3 mm to 1.5 mm, and most preferably from about 0.5 mm to about 1.0 mm.One of ordinary skill in the art to which the invention pertain canreadily determine, select and employ an appropriate depth/height of thedepression/protrusion based on the desired graft dimensions, whether ornot a pin will also be used, clinical application, etc., without undueexperimentation. Adjacent bone portions provided with interlockingpatterns, may be self-locking such that no other connecting means, forexample one or more pins, is necessary to form a unitary structure, ie.to hold the composite bone graft together. Alternatively, interlockingbone portions may be “locked” to form a unitary structure using otherconnection means, for example, one or more pins partially or entirelytraversing a dimension of the composite bone graft, where the dimensionis for example the height, width, or length of the composite bone graft.

Load-bearing. By the term “load-bearing” is intended for the purposes ofthe present invention a non-demineralized bone product for implantationin a patient at a site where the bone graft will be expected towithstand some level of physical load(s).

Locking pin. By the term “locking-pin” is intended forthe purposes ofthe present invention, one or more pins entirely or partially traversinga dimension of a composite bone graft which serve to hold the bone grafttogether, for example, two or more interlocking bone portions providedwith complementary patterns for example, a stepped pattern, may belocked using one or more pins, for example, one bone pin partiallytraversing the length of the graft.

Mechanical Strength. By the term “mechanical strength” is intended forthe purposes of the present invention, the ability of a bone allograftto withstand mechanical loads at an implant site without failing.

Materials properties. By the term “materials properties” is intended forthe purposes of the present invention, those properties present innormal fresh bone and include loading strength, compressive strength,tensile strength, and brittleness.

Normal bone. By the term “normal bone” is intended for the purposes ofthe present invention, fresh hydrated autogenous and/or fresh-frozenhydrated allograft bone tissue.

Osteoconductivity. By the tern “osteoconductivity” is intended for thepurposes of the present invention, the ability of a substance which byits presence conducts osteoinductive activity. Suitable osteoconductivematerials include but are not limited to, for example, one or morebiocompatible matrix materials. Suitable osteoconductive substancesinclude but are not limited to, for example, hydroxyapitate; collagen;any biocompatible matrix material including for example, polymericmatrix materials, bioglass, bioceramics, resorbable Biomaterials,bioabsorbable polymers, a plastic matrix, stainless steel, titanium, andcobalt-chromium-molybdenum alloy matrix; and substances includinghydroxyapitate, including for example, Osteoset™ produced by WrightMedical.

Osteoinductivity. By the term “osteoinductivity” is intended for thepurposes of the present invention, the ability of a substance to promotebone growth. Suitable osteoinductive substances include but are notlimited to, for example, autograft bone; allograft bone; Grafton™produced by Osteotech; DynaGraft™; demineralized cortical bone;demineralized cancellous bone; collagen including one or more growthfactors including for example Novus™ produced by Stryker Biotech;collagen including demineralized bone including for example DynaGraft™;cancellous bone; cortical bone; OpteoForm™ produced by the University ofFlorida; OsteoFill™ produced by the University of Florida; growthfactors including for example, bone morphogenic protein and transforminggrowth factor-β. Preferably, when a demineralized bone product is usedthe bone is demineralized to contain less than 6 wt % residual calcium,more preferably demineralized to contain 1 wt % to about 3 wt % residualcalcium, and most preferably demineralized to contain about 2 wt %residual calcium.

Parallelepiped By the term “parallelepiped” is intended for the purposesof the present invention, a six-faced polyhedron all of whose faces areparallelograms lying in pairs of parallel planes.

Polyhedron. By the term “polyhedron” is intended for the purposes of thepresent invention, a solid formed by plane faces, preferably formed bysix faces.

Protrusion. By the term “protrusion” is intended for the purposes of thepresent invention, an irregularity in a surface of a bone allografthaving a height of from 0.1 to 5.00 mm, preferably 0.3 to 3.0 mm, morepreferably 0.5 to 1.5 mm, and most preferably 0.75 mm to 1.2 mm. Theprotrusions can be discrete, continuous, or a combination thereof, andcan be of any shape including for example: irregular; pyrimidal;conical; cuboidal; rectangular; and cylindrical; or any combinationthereof. Further, a cross-section of a continuous or discrete protrusionmay be of any shape including for example: irregular; rectangular;square; oval; round; triangular; trapizoidal; and a regular or irregularcurve; or any combination thereof. The protrusions can be provided onthe bone allograft surface in a regular, symmetric pattern including forexample a linear pattern or in an irregular pattern.

Self-locking, interlocking pattern. By the term “self-locking,interlocking pattern” is intended for the purposes of the presentinvention, any complementary patterns provided on adjacent bone portionswhich enable the bone portions: to interlock, act as a unitarystructure, and the bone portions are held together, without the use ofany additional connecting means.

Stability. By the term “stability” is intended for the purposes of thepresent invention the ability of the present composite bone graft toremain at an implantation site without significantly shifting, rotating,or being extruded.

Stress. By the term “stress” is intended for the purposes of the presentinvention, load per unit cross-sectional area

Textured. By the term “textured” is intended for the purposes of thepresent invention, a composite bone graft having one or more texturedsurfaces provided on the surface of the composite bone graft where thesurface of the composite bone graft can be any surface or a portion ofany surface including a natural surface and/or a cut surface. Thetextured surface preferably includes a plurality of protrusions providedon the surface or a portion thereof, the protrusions of a shapeincluding for example, irregular; pyrimidal; conical; cuboidal;rectangular; trapizoidal; curved; and cylindrical; or any combinationthereof. The protrusions can be discrete, continuous, or a combinationthereof.

Therapeutically Beneficial. By the term “therapeutically beneficial” isintended any material which by its action or presence, bring about atherapeutic result in a patient. Such materials include but are notlimited to, for example, one or more of the following: osteoinductivesubstances, osteoconductive substances, and pharmaceutically activeagents. Such therapeutically beneficial substances may optionally beprovided with a carrier. Suitable osteoinductive substances include butare notlimited to, for example, autograft bone; allograft bone; Grafton™produced by Osteotech; DynaGraft™; demineralized cortical bone;demineralized cancellous bone; collagen including one or more growthfactors including for example Novus™ produced by Stryker Biotech;collagen including demineralized bone including for example DynaGraft™;cancellous bone; cortical bone; OpteoForm™ produced by the University ofFlorida; OsteoFill™ produced by the University of Florida; growthfactors including for example bone morphogenic protein, and transforminggrowth factor-β. Suitable osteoconductive substances include but are notlimited to, for example, hydroxyapitate; collagen; any biocompatiblematrix material including for example, polymeric matrix materials,bioglass, bioceramics, resorbable Biomaterials; bioabsorbable polymers;a plastic matrix; stainless steel; titanium; cobalt-chromium-molybdenumalloy matrix; and substances including hydroxyapitate, including forexample, Osteoset™ produced by Wright Medical. Suitable pharmaceuticallyactive agents include but are not limited to, for example, growthfactors including for example bone growth factors including for examplebone morphogenic protein, and transforming growth factor-β, andtransforming growth factorβ; chemotherapeutic agents; anti-inflammatoryagents; and antibiotics.

II. Procurement and Preliminary Processing of Bone Tissue

Suitable bone tissue includes bone obtained from any animal or humansource. Preferably, bone graft tissue can be obtained from the patienthimself (autologous bone) or from a cadaver (allograft bone). Whenallograft bone tissue is used, it is processed under strict asepticconditions in certified clean room operating suites. The bone tissue ispreferably processed to remove all soft tissue, including marrow andblood, to produce a cleaned bone graft. Suitable processing methods arewell known to those skilled in the art and can be readily selected andemployed by those of ordinary skill in the art without undueexperimentation. Suitable methods include the methods disclosed in, forexample, U.S. Pat. Nos.: 5,556,379; 5,820,581; and 5,797,891.

After processing, the cleaned grafts are packaged under sterileconditions and stored for latter processing into the present compositebone allograft, or immediately processed into the present composite boneallograft followed by appropriate packaging. The use of fresh-frozenand/or freeze-dried, bone allografts are preferred.

III. How to Make a Preferred Embodiment of the Composite Bone Graft

FIG. 11A illustrates a preferred method 60 of making the presentcomposite bone graft. A composite bone graft having of any sizenecessary for a particular application, can be made using the preferredmethod discussed hereafter. A cortical bone shaft 61 is obtained from acadaver and is transected into cortical sections 62 having a length 63of at least 18.0 mm, preferably at least 21.0 mm.

A cortical section 62 is then first cut to produce a cortical plank 64,the remaining cortical section 62 a is turned and again cut to produce asecond cortical plank, the remaining cortical plank 62 b is again turnedand cut into third and fourth cortical planks 64. The cortical planks 64are cut to an appropriate width 65 and thickness 66. The concave surface60 a of the plank 64 can be smoothed if needed to produce a smoothedplank 67. Opposing edges 60 a and 60 b can be cut such that the cutsurfaces 60 c and 60 d are approximately parallel. The cut width 68should be larger than the final composite bone graft width. Morespecifically, cut width 68 is preferably greater than about 12.0 mm.

The convex surface 60 b of plank 64 is then smoothed to produce asmoothed plank 69. The smoothed plank 64 is further smoothed by forexample, milling, such that the opposing surfaces 64 a and 60 b, and 60c and 60 d, are parallel, to produce a parallel plank 70 having athickness 71 of at least 1.0 mm, preferably from about 1.5 mm to about6.0 mm, and more preferably from about 2.0 mm to about 5.5 mm.

FIG. 11B illustrates cortical pins 7 cut from a cortical section 62,using for example a drill press 72 or other means known in the art Thecortical pins 7, can also be made from a cortical plank 64, for exampleby turning on a lathe. The pins 7 have a diameter of from about 1.0 toabout 6.0 mm, preferably from about 1.5 mm to about 4.5 mm, and morepreferably from about 2.0 mm to about 4.0 mm.

If the composite bone graft includes cancellous bone, cancellous boneplanks 73 are produced and sized by the method as described above forproducing cortical bone planks 69 and 70. The composite bone unit 74 isthen assembled as desired, for example a cortical parallel plank 70, acancellous plank 73, and another cortical parallel plank 70. Thecomposite bone unit 74 has a height 74 a, a width 74 b and a length 74c. The height 74 a, width 74 b and length 74 c, can be readily selectedby one of ordinary skill in the art, depending on factors including forexample, the particular application and site of implantation in apatient. The planks are secured and holes 5 are drilled there through.The through-holes 5 are sized such that a tight or frictional fit isprovided between a pin 7 and a though-hole 5. The cortical pins 7 arethen inserted through the through-holes 5, and pressed to fit if needed,to produce pinned composite graft 75. The cortical bone pins 7 have adiameter 8 sufficient to provide an interference fit or frictional fitbetween a pin 7 and a through-hole 5. More specifically the diameter 8of a cortical pin 7 is generally the same or slightly larger than thediameter 6 of a through-hole 5 into which it is to be inserted. Thediameter of the pin 7 is preferably no more than 1.5 mm larger than thediameter of the through-hole 5.

The assembled pinned graft can thereafter be shaped as desired, forexample into a trapezoid shaped graft and appropriately dimensioned toproduce a composite bone graft. One or more surfaces of the compositebone graft may be textured if desired, for example, depending upon theparticular application.

FIG. 12 illustrates an additional method 33 of making a preferredembodiment of the present composite bone graft. A cross-section of afemur is obtained from a cadaver, and cleaned using methods well knownto those of ordinary skill in the art to which the present inventionpertains, to remove bone marrow elements thereby producing the cleanedfemural ring 34. The cleaned femural ring is then sectioned into severalsections of cortical bone including a first cortical bone portion 35 anda second cortical bone portion 36, each portion having a width 37 offrom about 2.0 to about 10.0 mm; preferably of from about 4.0 to about8.0 mm; and more preferably of from about 5.0 to about 6.0 mm. Portions35 and 36 are then held together to form a graft unit 38 having a widthof 39 which is at least 4.0 mm; preferably greater than 9.0 mm; usingfor example, a clamp, and one or more through-holes 5 having a diameter6 of about 0.5 mm to about 10.0 mm, preferably 2.0 mm to about 5.0 mm,more preferably 2.0 mm to about 4.0 mm, are then drilled there through.

Cortical pins 7 are produced from cortical bone by methods well known tothose of ordinary skill in the art to which the present inventionpertains. The pins 7 have a diameter of from 1.0 mm to about 6.0 mm,preferably from about 1.5 mm to about 4.5 mm, and more preferably fromabout 2.0 mm to about 4.0 mm. The graft unit 38, having through-holes 5drilled there through is then placed in a press and one or more corticalpins 7 are inserted into the through-holes 5.

Thereafter, one or more surfaces 44 of the composite bone graft 45 canbe textured by for example, milling to create a desired textureincluding the illustrated continuous linear protrusions (sawtoothpattern). Preferably, the composite bone graft includes opposingtextured surfaces disposed perpendicular to the interface(s) of the boneportions.

FIG. 15 illustrates a preferred method for making a cervicalwedge(flattened curved wedge) composite bone graft. Cortical planks 70are produced and pinned using cortical pins 7 as previously described inFIGS. 11A and 11B to form a pinned cortical graft unit 89. The pinnedgraft unit 89 has a height 90, a length 91 and a width 92. The pinnedgraft unit 89 is then cut and shaped 94 to a designated pattern 93 toform a flattened curved block 95. A through-hole 83 is then providedcentrally through the flattened curved block 95 using for example adrill press 72. The top 96 and bottom 97 faces of the block 95 are thenprovided with a slope at an angle 98 for example by milling. The top 96and/or bottom 97 faces may optionally be textured, for example byproviding the faces with a plurality of pyrimidal protrusions.

FIG. 29 illustrates a method of making a composite bone graft 99including a discontinuous, demineralized, cortical bone portion 100disposed between two cortical bone portions 70. The cortical parallelplanks 70 are produced as discussed above in reference to FIG. 11. Thediscontinuous, demineralized, cortical bone portion 100 is produced byfirst producing a cortical parallel plank 70, as described above inreference to FIG. 11. The cortical parallel plank 70 is then perforated,for example using a drill press, to create perforations 101 traversingthe width of the plank, and to create channels 102 traversing the heightof the plank, to produce a discontinuous bone plank 103. Thediscontinuous bone plank 103 is then demineralized by any method wellknown to those of ordinary skill in the art, including for example,demineralizing in 0.5-0.6N hydrochloric acid at from 25° C. to 50° C.,preferably at from 25° C. to 37° C., for a period of time of from about1 hour to about 8 hours, preferably for about 2 hours, more preferablydemineralization is carried out until the discontinuous bone plank 103contains less than 6 wt % residual calcium, preferably about 1 wt % toabout 3 wt % residual calcium, and most preferably demineralized tocontain about 2 wt % residual calcium, to produce a demineralizeddiscontinuous plank 100. The demineralized discontinuous bone plank 100and the cortical parallel planks 70 are then assembled, shaped, andtextured to produce the composite bone graft 99, according to themethods described in reference to FIG. 11.

FIG. 30 illustrates a method of making a composite bone graft 105including a demineralized cancellous bone portion 106 disposed betweentwo cortical bone portions 70. The cortical parallel planks 70 areproduced as discussed above in reference to FIG. 11. The demineralizedcancellous bone portion 106 is produced by first producing a cancellousparallel plank 73, as described above in reference to FIG. 11. Thecancellous parallel plank 73 is then demineralized by any method wellknown to those of ordinary skill in the art, including for example,demineralizing in 0.5-0.6N hydrochloric acid at from 25° C. to 50° C.,preferably at from 25° C. to 37° C., for a period of time of from about20 minutes to about 6.0 hours, preferably for about 30 minutes to about2.0 hour to produce a demineralized cancellous bone plank 106. Morepreferably, demineralization is carried out until the bone plank 106produced, contains less than 6 wt % residual calcium, preferably about 1wt % to about 3 wt % residual calcium, and most preferably demineralizedto contain about 2 wt % residual calcium. The demineralized cancellousbone plank 106 and the cortical parallel planks 70 are then assembled,shaped, and textured to produce the composite bone graft 105, accordingto the methods described in reference to FIG. 11.

Composite bone grafts including two or more distinct cortical boneportions each bone portion provided with a pattern thereon to enable thebone portions to interlock or engage, are made by first making corticalbone planks as described. After the planks are made they are eachprovided with a pattern, for example a discrete or continuous pattern.The patterned planks are then fitted in together. The patterned planksmay be self-locking, ie. provided with a “key” type pattern, to form aunitary structure, or may be locked using one or more pins entirely orpartially traversing a dimension, ie. the graft's height, width, and/orlength. Thereafter, the locked graft is shaped to form the compositebone graft. Suitable patterns include any complementary patterns whichwhen provided on two or more adjacent bone portions, enable two or morebone portions to act as one, where the patterns are self-locking or arelocked with one or more additional connection means, including forexample one or more pins.

IV. Description of Preferred Embodiments of the Composite Bone Graft

The present composite bone graft provides a bone graft which can beappropriately sized for any application, has increased stability of thegraft at an implant site and promotes the ingrowth of patient bone,while providing excellent mechanical strength.

FIG. 1 illustrates a perspective view of a preferred composite bonegraft 1 including a first cortical bone portion 2, a second corticalbone portion 4, a cancellous bone portion 3 sandwiched between boneportions 2 and 4, a through-hole 5 having a diameter 6, and a corticalbone pin 7 having a diameter 8. The composite bone graft 1, has a length9, a posterior height 13, an anterior height 11, a composite width 12,and section widths 10 a, 10 b, and 10 c.

FIG. 2 illustrates a side view of a composite bone graft 1 havingopposing textured surfaces 14 a and 14 b provided perpendicular to theinterfaces of the bone portions. 14 a and 14 b illustrate continuouslinear protrusions defining a saw-tooth-like pattern.

FIG. 3 illustrates a cross-section posterior view of composite bonegraft 1, illustrating section widths 10 a, 10 b, and 10 c of boneportions 2, 3, and 4, respectively, and having an anterior height 11 andcomposite width 12.

FIG. 4 illustrates a cross-section anterior view of composite bone graft1, illustrating an posterior height 13 and composite width 12.

FIG. 5 illustrates a top view of composite bone graft 1 illustratingcortical bone portions 2 and 4, cancellous bone portion 3 disposed therebetween, and textured surface 14 b.

FIG. 6 is a perspective view of composite bone graft 1 illustratingcortical bone portions 2 and 4, cancellous bone portion 3 disposed therebetween, textured surfaces 14 a and 14 b, and cortical bone pins 7.

FIG. 7 illustrates a perspective of a preferred composite bone graft 15having a first cortical bone portion 16, a second cortical bone portion17, cortical bone pins 18, through-holes 19, and void 107, where thediameter of the through-holes 19 and the diameter of the cortical bonepins 18 are configured to allow a slidable connection between the boneportions 16 and 17, and the bone portions 16 and 17 and the corticalbone pins 18. The composite bone graft 15 includes a top texturedsurface 14 b and a bottom textured surface 14 a disposed perpendicularto an interface between bone portions 16 and 17. Composite bone graft 15may optionally include one or more cancellous or cortical bone portionsdisposed between and slidably connected to cortical bone portions 16 and17, and to cortical bone pins 18.

FIG. 8 illustrates a top view of composite bone graft 15 having a firstcortical bone portion 16, a second cortical bone portion 17, and acancellous bone portion 20 disposed there between, with one portions 16,17, and 20 being slidably connected with cortical bone pins 19. Thisgraft can be used in place of the traditional iliac crest wedge.

FIG. 9 illustrates a perspective view of a preferred composite bonegraft 21 including a first cortical bone portion 22, a second corticalbone portion 23, a third cortical bone portion 24, through-holes 5 andcortical bone pins 7.

FIG. 10 illustrates a preferred composite bone graft 25 including aplurality of cortical bone portions including a first cortical boneportion 26, a second cortical bone portion 27, a third cortical boneportion 28, a forth cortical bone portion 29, a fifth cortical boneportion 30, and a single cortical bone pin 31 inserted in through-hole32. This graft can be used in place of the traditional cloward dowel.

FIG. 13A is a perspective view of a preferred trapezoid block compositebone graft having opposing textured surfaces which include a pluralityof protrusions 80, and having a first cortical bone portion 2, a secondcortical bone portion 4, a cancellous bone portion 3 sandwiched betweenbone portions 2 and 4, through-holes 5, and a cortical bone pins 7having a diameter 8. The composite bone graft, has a length 9, aposterior height 13, an anterior height 11, a composite width 12,section widths 10 a, 10 b, and 10 c, a length 76 which is the length ofthe graft measured from the anterior end to the center of the first pin7, a length 77 which is the length of the graft measured from the centerpoint of a first pin 7 to a center point of a second pin 7, and a length78 which is the length of the graft measured from a center point of asecond pin to the posterior end of the graft. The textured surface isdetailed in FIG. 13B. The protrusions 80 have a height of 81, and arecut in a “saw-tooth” pattern at an angle of 79.

FIGS. 14A, 14B and 14C, illustrate a cervical wedge composite bone graft(flattened curved wedge composite bone graft) for use in cervicalfusions where 14A is a perspective standing view, 14B is a side view,and 14C is a perspective view where the graft is provided with opposingtextured surfaces. The flattened curved wedge composite bone graftincludes first and second cortical bone portions 82 held together by twocortical bone pins 7 to form a pinned graft unit, and the pinned graftunit having a hole 83 disposed there through located between pins 7. Thecervical fusion graft has a diameter 84, a width 85, an front compositewidth 87, and a back composite width 86. The cervical fusion graft asshown in FIG. 14C has textured opposing faces which include a pluralityof pyrimidal protrusions 88.

FIG. 16 illustrates a perspective view of a mechanical connector 46having a slot 47 extending from its lower end.

FIG. 17 illustrates a side view of mechanical connector 46 having a slot47 extending from its lower end.

FIG. 18 illustrates a cross-section view of mechanical connector 46having a slot 47 extending from its lower end.

FIG. 19 illustrates a perspective view of a mechanical connector 48having a plurality of horizontally disposed grooves 49.

FIG. 20 illustrates a perspective view of a mechanical connector 50having helical threads 51.

FIG. 21 illustrates a perspective view of a mechanical connector 52having a plurality of vertically disposed grooves 53.

FIG. 22 illustrates a perspective view of a mechanical slotted pinconnector 54.

FIG. 23 illustrates a perspective view of a mechanical connector 55having a plurality of horizontally disposed ridges 56.

FIG. 24 illustrates a perspective view of a mechanical triangular pinconnector 57.

FIG. 25 illustrates a perspective view of a mechanical square pinconnector 58.

FIG. 26 illustrates a perspective view of a mechanical hexagon pinconnector 59.

FIG. 27 illustrates a perspective view of a rectangular block compositebone graft 99, including a first cortical bone portion 2, a secondcortical bone portion 4, a discontinuous, demineralized cortical boneportion 104 disposed between cortical bone portions 2 and 4, where thediscontinuous, demineralized cortical bone portion 100 includesperforations traversing the width of the bone portion 100 and aredisposed perpendicular to the interfaces of the bone portions 2, 100 and4, and channels 102 traversing the height of bone portion 100 and aredisposed parallel to the interfaces of the bone portions 2, 100, and 4,through-holes 5, and cortical bone pins 7. The composite bone graft 99includes opposing textured surfaces 14 a and 14 b provided perpendicularto the interfaces of the bone portions and defining a saw-tooth-likepattern.

FIG. 28 illustrates a perspective view of a rectangular block compositebone graft 105, including a first cortical bone portion 2, a secondcortical bone portion 4, a demineralized cancellous bone portion 106disposed between cortical bone portions 2 and 4, through-holes 5, andcortical bone pins 7. The composite bone graft 105 includes opposingtextured surfaces 14 a and 14 b provided perpendicular to the interfacesof the bone portions and defining a saw-tooth-like pattern.

FIG. 31A illustrates a top view of a rectangular block composite bonegraft 108, including a first cortical bone portion 2, a second corticalbone portion 4, a void 107 disposed between cortical bone portions 2 and4, and cortical bone pins 7. The void 107 includes one or moretherapeutically beneficial substances 109.

FIG. 31B illustrates a perspective view of a rectangular block compositebone graft 108, including a first cortical bone portion 2, a secondcortical bone portion 4, a void 107 disposed between cortical boneportions 2 and 4, through-holes 5, and cortical bone pins 7. The void107 includes one or more therapeutically beneficial substances 109. Thecomposite bone graft 108 includes opposing textured surfaces 14 a and 14b provided perpendicular to the interfaces of the bone portions 2 and 4,with the therapeutically beneficial substance 109, and defining asaw-tooth-like pattern.

FIGS. 32A, 32B and 32C, illustrate a parallel block composite bone graftwhere 32A is a cross-section view, 32B is a top-view, and 32C is a is aside view of the width of the composite graft., where the graft isprovided with opposing textured surfaces. The composite bone graftincludes first and second cortical bone units 110, a cancellous boneportion 3 sandwiched between bone units 110, through-holes 5, and acortical bone pins 7 (The diameter of each bone pin may be the same ordifferent depending on the particular application, implant and size ofthe graft, the diameter of a pin is preferably about 1.0 to about 5.0mm, more preferably from about 1.5 mm to about 4.0 mm, even morepreferably from about 2.0 to about 3.5 mm, and most preferably 2.5 to3.0 mm). The composite bone graft, has a length 9 (preferably from 5.0to about 50.0 mm, more preferably from about 10.0 to about 30.0 mm, evenmore preferably from about 15.0 mm to about 25.0 mm, and most preferablyabout 21.0 mm), a height 112 (preferably from about 3.0 mm to about 30.0mm, more preferably from about 5.0 mm to about 25.0 mm, even morepreferably from about 8.0 mm to about 15.0 mm), a composite width 12(preferably from about 4.0 mm to about 20.0 mm, more preferably fromabout 5.0 mm to about 15.0 mm), section widths 10 a, 10 b, and 10 c,which are preferably 4.0 mm, 3.0 mm, and 4.0 mm; 4.0 mm, 5.0 mm, and 4.0mm; and 3.0 mm, 5.0 mm, and 3.0 mm; respectively, where two boneportions 111 are layered to form the bone unit 110, and where the widthof each bone portion 111 is such that when layered with another boneportion 111, the resultant width 113 is as desired, for example, 4.0 mm.The bone graft has a length 76 (for example when the length of the graftis 21.0 mm, length 76 is preferably about 7.5 mm) which is the length ofthe graft measured from the anterior end to the center of the first pin7, a length 77 (for example when the length of the graft is 21.0 mm,length 77 is preferably about 8.0 mm) which is the length of the graftmeasured from the center point of a first pin 7 to a center point of asecond pin 7, and a length 78 (for example when the length of the graftis 21.0 mm, length 78 is preferably about 5.5 mm) which is the length ofthe graft measured from a center point of a second pin to the posteriorend of the graft. The protrusions 80 have a height of 81 (preferablyfrom about 0.5 mm to about 2.5 mm, more preferably from about 1.0 mm toabout 2.0 mm, and most preferably from about 1.1 mm to about 1.6 mm),and are cut in a “saw-tooth” pattern at an angle (preferably about 60°).

FIGS. 33A, 33B, and 33C, illustrate a trapezoid wedge composite where33A is a cross-section view, 33B is a top-view, and 33C is a side viewof the width of the composite graft. The composite bone graft includesfirst and second cortical bone units 110, a cancellous bone portion 3sandwiched between bone units 110, through-holes 5, and a cortical bonepins 7 (The diameter of each bone pin may be the same or differentdepending on the particular application, implant and size of the graft,the diameter of a pin is preferably about 1.0 to about 5.0 mm, morepreferably from about 1.5 to about 4.0 mm, even more preferably fromabout 2.0 to about 3.5 mm, and most preferably 2.5 to 3.0 mm). Thecomposite bone graft, has a length 9 (preferably from 5.0 to about 50.0mm, more preferably from about 10.0 to about 30.0 mm, even morepreferably from about 15.0 mm to about 25.0 mm, and most preferablyabout 21.0 mm), an anterior height 11 (preferably from about 3.0 mm toabout 30.0 mm, more preferably from about 5.0 mm to about 25.0 mm, evenmore preferably from about 8.0 mm to about 15.0 mm), a posterior height13 (preferably from about 5.0 mm to about 50.0 mm, more preferably fromabout 7.0 mm to about 25.0 mm, and even more preferably from about 10.0to about 15.0 mm), a composite width 12 (preferably from about 4.0 mm toabout 20.0 mm, more preferably from about 5.0 mm to about 15.0 mm,section widths 10 a, 10 b, and 10 c, which are preferably 4.0 mm, 3.0mm, and 4.0 mm; 4.0 mm, 5.0 mm, and 4.0 mm; and 3.0 mm, 5.0 mm, and 3.0mm; respectively, where two bone portions 111 are layered to form thebone unit 110, and where the width of each bone portion 111 is such thatwhen layered with another bone portion 111, the resultant width 10 a or10 c is as desired, for example, 4.0 mm. The bone graft has a length 76(for example when the length of the graft is 21.0 mm, length 76 ispreferably about 7.5 mm) which is the length of the graft measured fromthe anterior end to the center of the first pin 7, a length 77 (forexample when the length of the graft is 21.0 mm, length 77 is preferablyabout 8.0 mm) which is the length of the graft measured from the centerpoint of a first pin 7 to a center point of a second pin 7, and a length78 (for example when the length of the graft is 21.0 mm, length 78 ispreferably about 5.5 mm) which is the length of the graft measured froma center point of a second pin to the posterior end of the graft. Theprotrusions 80 have a height of 81 (preferably from about 0.5 mm toabout 2.5 mm, more preferably from about 1.0 mm to about 2.0 mm, andmost preferably from about 1.1 mm to about 1.6 mm), and are cut in a“saw-tooth” pattern at an angle (preferably about 60°).

FIG. 34 illustrates a trapezoid wedge composite bone graft 113 includinga first cortical bone portion 2, a second cortical bone portion 4,opposing textured surfaces 14 a and 14 b, vertically disposed channels114 (preferably channels 114 have a diameter of from 0.25 mm to about5.0 mm, more preferably from about) 0.5 mm to about 4.0 mm, and mostpreferably from about 1.0 mm to about 3.0 mm), and horizontally disposedchannel 115 (preferably channels 115 have a diameter of from about 0.5to about 6.0 mm, more preferably from about 1.0 mm to about 5.0 mm, andmost preferably from about 2.0 mm to about 4.0 mm). The composite bonegraft also includes cortical bone pins 7 (preferably bone pins 7 have adiameter of from about 2.0 mm to about 3.5 mm, more preferably fromabout 2.5 mm to about 3.0 mm, where each pin may have the same or adifferent diameter) and through-holes 5. The channels may optionallyinclude one or more therapeutically beneficial substances. The graft hasa length 9 (preferably from 5.0 to about 50.0 mm, more preferably fromabout 10.0 to about 30.0 mm, even more preferably from about 15.0 mm toabout 25.0 mm, and most preferably about 21.0 mm), an front height 11(preferably from about 3.0 mm to about 30.0 mm, more preferably fromabout 5.0 mm to about 25.0 mm, even more preferably from about 8.0 mm toabout 15.0 mm), a back height 13 (preferably from about 5.0 mm to about50.0 mm, more preferably from about 7.0 mm to about 25.0 mm, and evenmore preferably from about 10.0 to about 15.0 mm), a composite width 12(preferably from about 4.0 mm to about 20.0 mm, more preferably fromabout 5.0 mm to about 15.0 mm and most preferably about 6.0 mm to about8.0 mm), and a section width 116 (preferably from about 1.0 mm to about5.0 mm, more preferably from about 2.0 mm to about 4.0 mm, and mostpreferably from about 3.0 mm to about 3.5 mm).

FIG. 35A illustrates a standing view of a cervical wedge composite bonegraft-having a textured surface 117 a. The cervical wedge composite bonegraft includes first and second cortical bone portions 82 held togetherby two cortical bone pins 7 to form a pinned graft unit, and the pinnedgraft unit having a through-hole 83 (preferably from about 2.0 mm toabout 8.0 mm in diameter, more preferably from about 3.0 mm to about 5.0mm) disposed there through located between pins 7. The cervical fusiongraft has a diameter 84, a width 85, a front composite width 87, and aback composite width 86. The cervical wedge also includes horizontallydisposed channels 115 (preferably channels 115 have a diameter offromabout 0.5 to about 10.0 mm, more preferably from about 1.0 mm to about5.0 mm, and most preferably from about 2.0 mm to about 4.0 mm), and oneor more therapeutically beneficial substances 109, for examplecancellous bone or demineralized cancellous bone, disposed inthrough-hole 83 and/or channels 115. FIG. 35B illustrates aside view ofthe cervical wedge composite bone graft of FIG. 35A and includesopposing textured surfaces 117 a and 117 b, and a vertically disposedchannel 118. The top and bottom surfaces of the graft are sloped atangel 119 and 120, respectively. Angle 119 is preferably from about 0°to about 10°, more preferably from about 0° to about 7°, and in thisfigure it is 0°. Angle 120 is preferably from about 0° to about 10°,more preferably from about 0° to about 7°, and in this figure the angleis 7°, that is the graft slopes at 7°.

FIGS. 36A, 36B, and 36C, illustrate a trapezoid wedge composite bonegraft including two cortical bone portions where 36A is a cross-sectionview, 36B is a top-view, and 36C is a side view of the width of thecomposite graft. The composite bone graft includes first and secondcortical bone portions 2 and 4, through-holes 5, and a cortical bonepins 7 (The diameter of each bone pin may be the same or differentdepending on the particular application, implant and size of the graft,the diameter of a pin is preferably about 1.0 to about 5.0 mm, morepreferably from about 1.5 to about 4.0 mm, even more preferably fromabout 2.0 to about 3.5 mm, and most preferably 2.5 to 3.0 mm). Thecomposite bone graft, has a length 9 (preferably from 5.0 to about 50.0mm, more preferably from about 10.0 to about 30.0 mm, even morepreferably from about 15.0 mm to about 25.0 mm, and most preferablyabout 21.0 mm to 23 mm), an anterior (shorter) height 11 (preferablyfrom about 3.0 mm to about 30.0 mm, more preferably from about 5.0 mm toabout 25.0 mm, even more preferably from about 8.0 mm to about 15.0 mm),a posterior (longer) height 13 (preferably from about 5.0 mm to about50.0 mm, more preferably from about 7.0 mm to about 25.0 mm, and evenmore preferably from about 10.0 to about 15.0 mm), a composite width 12(preferably from about 4.0 mm to about 20.0 mm, more preferably fromabout 5.0 mm to about 15.0 mm, section widths 124, which are preferablyfrom about 2.0 mm to about 5.0 mm, more preferably from about 2.5 mm toabout 4.0 mm, and most preferably about 3.5 mm±0.5 mm. The bone grafthas a length 122 (for example when the length of the graft is 23.0 mm,length 122 is preferably about 5.5 mm) which is the length of the graftmeasured from the posterior (longer) end to the center of the first pin7, a length 123 (for example when the length of the graft is 23.0 mm,length 123 is preferably about 13.5 mm) which is the length of the graftmeasured from the posterior (longer) end to the center point of thesecond pin 7. The graft is chamfered at diametrically opposed edgesincluding edge 140 at an angle 125 of preferably about 45° at a depth126 of preferably about 0.5 mm. The wedge graft has a slope 121 ofpreferably from about 3.0° to about 13.0°, more preferably from about5.0° to about 11.0°, and most preferably about 5.4° or 10.8° dependingon the anterior and posterior heights.

FIG. 37 illustrates a cross-section view of a cervical wedge compositebone graft (flattened curved wedge composite bone graft) for use incervical fusions. The flattened curved wedge composite bone graftincludes two or more cortical bone portions held together by twocortical bone pins 7 to form a pinned graft unit, and the pinned graftunit having a hole 83 disposed there through located between pins 7 andhaving a diameter 130 of from about 3.0 mm to about 7.0 mm, morepreferably; from about 4.0 mm to about 6.0 mm, and most preferably about4.0 mm to 5.0 mm. The distance 127 between hole 83 and second width 129,and between pins 7 and arc 137, is preferably 1.0 mm to 3.5 mm, morepreferably about 1.5 mm to about 3.0 mm and even more preferably about2.0 mm. The distance 128 between hole 83 and pins 7 is preferably from1.5 mm to 3.5 mm, more preferably from 2.0 mm to about 3.0 mm, and mostpreferably is about 2.25 mm to 2.75 mm. The cervical fusion graft has adiameter 84 of from about 10.0 mm to about 20.0 mm, more preferably fromabout 12.0 mm to about 16.0 mm, and most preferably about 12.0 mm to14.0 mm, a width 85 of from about 14.0 mm to about 24.0 mm, morepreferably from about 15.0 mm to about 20.0 mm, and most preferablyabout 15.5 mm to 17.5 mm, and a second width 129 of from about 8.0 mm toabout 16.0 mm, more preferably from about 10.0 mm to about 14.0 mm, andmost preferably about 11.0 mm to 12.0 mm. Slope 136 is preferably about15° to about 30°, more preferably about 20° to about 25°, and mostpreferably about 20°.

FIG. 38 illustrates a cross-section view of a cervical wedge compositebone graft (flattened curved wedge composite bone graft) for use incervical fusions. The flattened curved wedge composite bone graftincludes two or more cortical bone portions held together by twocortical bone pins 7 to form a pinned graft unit, and the pinned graftunit having a hole 83 disposed there through located between pins 7 andhole 83 having a height 131 of from about 5.0 mm to about 15.0 mm, morepreferably from about 6.0 mm to about 12.0 mm, and most preferably about8.0 mm to 10.0 mm, and having a width 130 of from 3.0 mm to about 7.0mm, more preferably from about 4.0 mm to about 6.0 mm, and mostpreferably about 4.0 mm to 5.0 mm. The distance 127 between hole 83 andsecond width 129, and between pins 7 and arc 137, is preferably 1.0 mmto 3.5 mm, more preferably about 1.5 mm to about 3.0 mm and even morepreferably about 2.0 mm. The distance 128 between hole 83 and pins 7 ispreferably from 1.5 mm to 3.5 mm, more preferably from 1.0 mm to about3.0 mm, and most preferably is about 2.0 mm. The cervical fusion grafthas a diameter 84 of from about 10.0 mm to about 20.0 mm, morepreferably from about 12.0 mm to about 16.0 mm, and mostpreferably about12.0 mm to 14.0 mm, a width 85 of from about 14.0 mm to about 24.0 mm,more preferably from about 15.0 mm to about 20.0 mm, and most preferablyabout 15.5 mm to 17.5 mm, and a second width 129 of from about 8.0 mm toabout 16.0 mm, more preferably from about 10.0 mm to about 14.0 mm, andmost preferably about 11.0 mm to 12.0 mm. Slope 136 is preferably about15° to about 30°, more preferably about 20° to about 25°, and mostpreferably about 20°.

FIG. 39 illustrates a perspective view of a preferred composite bonegraft including cortical bone portions 132, and a cortical bone pins 7.The cortical bone portions 132 are patterned with grooves 133 running indirection 135 to provide an interlocking fit between the bone portions132.

FIGS. 40A and 40B illustrate a wedge composite bone graft (flattenedcurved wedge composite bone graft) for use in cervical fusions where 14Ais a standing side view, and 14B is a perspective view. The flattenedcurved wedge composite bone graft includes first and second corticalbone portions 132 held together by two cortical bone pins 7 to form apinned graft unit, and the pinned graft unit having a hole 83 disposedthere through located between pins 7. The cortical bone portions 132 arepatterned with grooves 133 running in direction 135 to provide aninterlocking fit between the bone portions 132.

FIG. 41 illustrates a perspective view of a preferred composite bonegraft including cortical bone portions 132 and 134, and a cortical bonepins 7. The cortical bone portions 132 and 134 are patterned withgrooves 133 running in direction 135 to provide an interlocking fitbetween the bone portions 132.

FIGS. 42A, 42B, and 42C illustrate side views of a preferred compositebone graft including two patterned cortical bone portions 132 having apattern 133, 138, and 139, respectively, where the bone portions areinterlocked with each other. FIG. 42C illustrates a self-locking,interlocking pattern 139.

FIG. 43 illustrates a cross-section view of a cervical wedge compositebone graft (flattened curved wedge composite bone graft) for use incervical fusions. The flattened curved wedge composite bone graftincludes two or more cortical bone portions held together by twocortical bone pins 7 having a diameter of from 1.0 mm to about 4.0 mm,preferably from about 2.0 mm to about 3.0 mm and more preferably about2.5 mm, to form a pinned graft unit, and the pinned graft unit having ahole 83 disposed there through located between pins 7, and hole 83having a width 130 of from 3.0 mm to about 7.0 mm, more preferably fromabout 4.0 mm to about 6.0 mm, and most preferably about 4.0 mm to 5.0mm. The distance 127 between 83 and second width 129, and between pins 7and arc 137, is preferably 1.0 mm to 3.5 mm, more preferably about 1.5mm to about 3.0 mm and even more preferably about 2.0 mm. The distance128 between hole 83 and pins 7 is preferably from 1.5 mm to 3.5 mm, morepreferably from 1.0 mm to about 3.0 mm, and most preferably is about 2.0mm. The cervical fusion graft has a diameter 84 of from about 10.0 mm toabout 20.0 mm, more preferably from about 12.0 mm to about 16.0 mm, andmost preferably about 11.0 mm to 13.0 mm, a width 85 of from about 10.0mm to about 24.0 mm, more preferably from about 12.0 mm to about 20.0mm, and most preferably about 13.5 mm to 15.5 mm, and a second width 129of from about 4.0 mm to about 12.0 mm, more preferably from about 6.0 mmto about 10.0 mm, and most preferably about 7.0 mm to about 8.0 mm.Slope 136 is preferably about 25°.

FIG. 44 illustrates a cross-section view of a cervical wedge compositebone graft (flattened curved wedge composite bone graft) for use incervical fusions. The flattened curved wedge composite bone graftincludes two or more cortical bone portions held together by twocortical bone pins 7 having a diameter of from 1.0 mm to about 4.0 mm,preferably from about 2.0 mm to about 3.0 mm and more preferably about2.5 mm, to form a pinned graft unit, and the pinned graft unit having ahole 83 disposed there through located between pins 7, and hole 83having a diameter 130 of from 3.0 mm to about 9.0 mm, more preferablyfrom about 4.0 mm to about 8.0 mm, and most preferably about 6.0 mm to7.0 mm, and a width 141 of from about 5.0 mm to about 13.0 mm,preferably from about 7.0 mm to about 11.0 mm, more preferably fromabout 8.5 mm to about 9.5 mm, and most preferably about 9.0 mm. Hole 83has a second width 140 of from about 2.0 mm to about 6.0 mm, preferablyfrom about 3.0 mm to about 5.0 mm, and more preferably form about 3.5 mmto about 4.5 mm. The distance 127 between hole 83 and second width 129,and between pins 7 and arc 137, is preferably 1.0 mm to 3.5 mm, morepreferably about 1.5 mm to about 3.0 mm and even more preferably about2.0 mm. The cervical fusion graft has a diameter 84 of from about 10.0mm to about 20.0 mm, more preferably from about 12.0 mm to about 16.0mm, and most preferably about 13.0 mm to 15.0 mm, a width 85 of fromabout 10.0 mm to about 24.0 mm, more preferably from about 12.0 mm toabout 20.0 mm, and most preferably about 16.5 mm to 18.5 mm, and asecond width 129 of from about 6.0 mm to about 14.0 mm, more preferablyfrom about 8.0 mm to about 12.0 mm, and most preferably about 9.0 mm to11.0 mm. Slope 136 is preferably about 25°.

The present composite bone graft can include two or more bone portions,including any combination of cancellous and cortical bone portions, orcancellous or cortical bone portions alone, where the bone portions mayoptionally be demineralized, and may optionally be discontinuous, wherethe bone portions are connected, for example by interlocking the boneportions, and/or by one or more mechanical and/or chemical connectors.Any cancellous bone portion and/or discontinuous bone portion (corticaland/or cancellous), and/or any demineralized bone portion (corticaland/or cancellous) may optionally include one or more pharmaceuticallyactive agents or therapeutically beneficial substances provided therein,for example provided in the matrix of cancellous bone, or provided inany artificially created void areas. Both the cortical and cancellousbone portions may be solid and continuous or may be discontinuous (i.e.include one or more “holes” or “perforations” of any shape disposed atregular or random intervals throughout the bone portion. Bone portionsmay be provided with a pattern to enable an interlocking fit betweencortical bone portions.

Suitable mechanical connectors include pin-type structures having anycross-section shape, such shapes including for example, round, square,triangular, rectangular, hexagon, pentagon, oval, and irregular. Thepin-type structure can include surface modification, for example thesurface can be roughened, or provided with a plurality of horizontallyor vertically disposed grooves (horizontal or vertically relative to thelength of the pin); horizontally or vertically disposed ridges; orhelical threads. The pin or surface-modified pin can also include one ormore slots extending partially or entirely through the diameter of thepin, and extending partially or entirely through the length of the pin,suitable slots include for example, a slot extending partially throughthe diameter of the pin, for example about half-way through the diameterof the pin, and through the entire length of the pin; and a slotextending entirely through the diameter of the pin, and extendingthrough a partial length of the pin for example, extending at leasthalf-way through the length of the pin, preferably extending no morethan about seven-eighths the length of the pin. Suitable mechanicalconnectors also include cotter pins. A composite graft can be pinnedwith one or more biocompatible pins, where the pins have substantiallythe same diameter or have a diameter different from each other. Suitablediameters can be readily selected and employed by one of ordinary skillin the art to which the present invention pertains without undueexperimentation depending upon, for example, the particular applicationand implantation site, and the size and shape of the composite graft.The composite graft can be pinned with one or more biocompatible pins,entirely or partially traversing a dimension of the graft, for example,the height, length, and/or width of the composite graft. One of ordinaryskill in the art to which the present invention pertains can readilyselect an appropriate pin, number of pins, and determine the orientationof the pin or pins, based on for example, the particular graft, whetherthe graft is interlocking or not, the orientation of the graft in thebody, and the clinical indication, without undue experimentation.

Suitable chemical connectors include any biocompatible adhesive. Suchadhesives are well known to those of ordinary skill in the art to whichthe present invention pertains, and can be readily selected and employedby those of ordinary skill in the art, without undue experimentation.Suitable chemical connectors also include known methods of biochemicalsurface modification. Such methods are well known to those of ordinaryskill in the art to which the present invention pertains, and can bereadily selected and employed by those of ordinary skill in the art,without undue experimentation.

The chemical and/or mechanical connectors may be used alone or in anycombination and may include one or more therapeutically beneficialsubstances including for example, one or more osteoinductive substances,one or more osteoconductive substances and one or more pharmaceuticallyactive agents.

The through-hole(s) of the composite bone graft may also include surfacemodification as described above for the present mechanical connectorsconfigured to accomadate a particular mechanical connector. For example,if a threaded cortical bone pin is used, the through-hole or holes canoptionally be threaded. The through-hole(s) can traverse any dimensionof the graft, provided that they are placed such that when graft unit isconnected the graft is held together. One of ordinary skill in the artto which the present invention pertains can readily select an optimumlocation for the through-holes based on criteria including thefollowing: the anterior and posterior height of the composite bonegraft, and the diameter of the mechanical and/or mechanical and chemicalconnectors, and the height of the protrusions. For example, when theanterior height is relatively small (i.e. 7.0 mm) and the diameter ofthe pin is relatively large (i.e. 2.5-3.0 mm), the through-holes can bespaced equidistant along the length of the graft unit, or displacedtoward the posterior end of the graft unit.

The graft unit can be connected with one or more mechanical connectors.Suitable connection include any connection which is adequate to hold thebone portions of the graft unit together. Such connections include, forexample, an interference or friction connection where the diameter ofthe pin is the same as or slightly larger than (preferably no more than1.5 mm larger than the diameter of the through-hole) the diameter of thecorresponding through-hole; a slidable connection where the diameter ofthe pin is the slightly less than the diameter of the through-hole, anda compression fit, where the pin is configured to allow compression uponinsertion where the pin expands after insertion, achieved for example,by providing the pin with a slot.

The mechanical connector of the invention, including pin-like connectorscan be composed of any biocompatible material sufficient to holdtogether the present graft unit. Suitable biocompatible materialsinclude for example, cortical bone; stainless steel; titanium;cobalt-chromium-molybdenum alloy; and a plastic for example, of one ormore of the following: nylon, polycarbonate, polypropylene, polyacetal,polyethylene, and polysulfone, where the plastic can optionally includefibers; and a polymer including one or more bioabsorbable polymersincluding resorbable calcium phosphates; bioceramics and/or glassesincluding for example bioactive glasses and glass-ceramics; and calciumphosphate ceramics. Such mechanical connectors including for example,bioabsorbable polymers may optionally include one or more active agents,including for example one or more pharmaceutically active agents and/orone or more therapeutically beneficial agents, provided on the surfaceor impregnated in the matrix of the material.

The surface of the mechanical connector can be modified by methods wellknown to those of ordinary skill in the art to which the inventionpertains, and include for example the following: (a) modification toinfluence cell adhesion and growth, provided by: (I) oxidizedpolystyrene surface, (ii) ammonia plasma-treated surface, and (iii)plasma-deposited acetone or methanol film; (b) modification to controlprotein adsorption; and (c) modification to improve lubricity.

The composite bone graft preferably has a shape including for example, asquare, rectangular or curved block; a flattened curved wedge (ie. acervical wedge for use in cervical fusion); a wedge; a trapezoid wedge;a polyhedron block, a parallelepiped; a cylinder or dowel having auniform diameter or a decreasing or increasing diameter, for example atapered cylinder or tapered dowel; a dowel or tapered dowel having across-section of a shape including for example, round, oval, square,rectangular, triangular, pentagon, or hexagon.

The composite bone graft can include one or more partially or completelytextured surfaces. Preferably, a textured composite bone graft includesopposing textured surfaces disposed perpendicular to the interface(s) ofthe bone portions. The textured surface of the composite bone graftincludes a plurality of protrusions. The protrusions can be formed overan entire surface of the composite bone graft or over a portion of asurface, for example over the entire cut surfaces, or over a portion ofthe cut surfaces. The plurality of protrusions can be formed on thesurface in any number of ways well known to those of ordinary skill inthe art to which the present invention pertains, including for examplemechanical and/or chemical methods, including for example, by forming aseries of parallel linear or curved grooves. The bone allograftprotrusions can be formed by milling, for example by milling a set ofparallel linear groves to form a saw-tooth configuration on the cutsurface of the composite graft to form continuous linear protrusions; bymilling a first set of parallel linear groves followed by turning thegraft and forming a second set of parallel grooves at an angle to thefirst series, for example, at a 90° angle to form a plurality ofdiscrete pyrimidal protrusions. Milling is preferably achieved , by forexample: running the graft over a milling tool which includes aplurality of closely spaced blades which can be adjusted to achieve adesired height and width; to form the discrete pyrimidal protrusions,the graft can then be turned at, for example, a 90° angle and again runover the milling tool to produce the discrete protrusions illustrated.Milling can also be achieved using for example a routing or dremel tool,a laser, and masking and acid etching.

Other protrusions, for example concentric rings or other curved orirregular, or regular protrusions can be provided by attaching a drillbit having a blade corresponding to the protrusion pattern desired wherethe blade is appropriately sized to provide a desired protrusion width,length, and height, to a drill and drilling the desired surface of thebone to achieve the desired textured surface. One of ordinary skill inthe art can readily design and produce, or select, and employ anappropriate milling tool to achieve a desired textured surface on a boneallograft, without undue experimentation.

Preferably, the protrusions (discrete, continuous, or a combinationthereof) present on one or more surfaces of the present allograft areclosely spaced, preferably from about 0.0 to 3.0 mm apart, preferably0.1 to 2.0 mm apart, more preferably about 0.2 to 1.5 mm apart, and mostpreferably about 0.5 mm apart, (that is, there is preferably a distanceof from 0.0 to 3.0 mm between the edges of two adjacent protrusions).The protrusions preferably have a height of from 0.1 to 5.00 mm,preferably 0.3 to 3.0 mm, more preferably 0.5 to 1.5 mm, and even morepreferably 0.75 mm to 1.3 mm, and most preferably about 1.2 mm.

The composite bone graft may include one or more void areas. Examples ofsuch grafts include a composite graft having for example a first and asecond cortical bone portion where the bone portions are for exampleslidably connected with for example one or more bone pins, where thefirst and second bone portion are disposed apart thereby creating acentrally located void. The void may optionally include anypharmaceutically active agent and/or therapeutically beneficial agent,including for example, osteoinductive substances including for example,bone morphogenic protein, hydroxyapitate, demineralized bone and boneproducts including for example GRAFTON and DYNEGRAFT, and autograftbone; such substances may be in any form including for example, in theform of a paste, gel, or sponge.

IV. Use of the Composite Bone Grafts

The present composite bone grafts are useful in spinal applicationsincluding restoration of column support and are preferably used from theposterior approach. Composite grafts suitable for posterior lumbarinterbody fusions include for example the following described in detailbelow: (a) composite bone grafts having a trapezoid wedge shape andoptionally having opposing textured surfaces disposed perpendicular tothe interfaces of the bone portions, (b) composite bone grafts having aparallel block shape and optionally having opposing textured surfacesdisposed perpendicular to the interfaces of the bone portions, (c)composite bone grafts having a large square block shape and optionallyhaving opposing textured surfaces disposed perpendicular to theinterfaces of the bone portions, (d) composite bone graft blocks havinga flattened curved wedge shape and optionally having opposing texturedsurfaces disposed perpendicular to the interfaces of the bone portionsfor use in for example, cervical fusion, (which can be used from ananterior or posterior approach) and (e) composite bone grafts having anovoid wedge shape for performing anterior fusions (which can be usedfrom an anterior or posterior approach).

The term “about” used below and throughout this disclosure in referenceto specific dimensions means that the tolerance limits for overall orouter dimensions of the composite bone graft is plus or minus (+/−) 1.0mm, and the tolerance limits for the width of individual cortical boneportions is plus or minus (+/−) 0.5 mm.

The composite bone grafts having a trapezoid wedge shape, the shape asshown in FIG. 1, and optionally having opposing textured surfacesdisposed perpendicular to the interfaces of the bone portions,preferably include two or more bone portions where the bone portions canbe cortical or cancellous bone portions or a combination thereof, eachbone portion having a width of from about 1.5 mm to about 10.0 mm,preferably from about 2.0 mm to about 7.0 mm, more preferably from about2.0 mm to about 5.0 mm, and most preferably having a width of about 2.0mm to about 4.0 mm, to give a composite width of from about 8.0 mm toabout 15.0 mm, preferably from about 9.0 mm to about 13.00 mm, and morepreferably about 11.0 mm.

The trapezoid wedge composite bone graft has a front (anterior) heightwhich is smaller than its back (posterior) height, the anterior heightbeing from about 5.0 mm to about 15.0 mm, preferably from about 6.0 mmto about 13.0 mm, more preferably from about 7.0 mm to about 12.0 mm,and most preferably about 8.0 mm, 9.0 mm, 10.0 mm, 12.0 mm, or 14.0 mm;the posterior height being from about 7.0 mm to about 20.0 mm,preferably from about 8.0 mm to about 17.0 mm, more preferably fromabout 9.0 mm to about 15.0 mm, and most preferably the posterior heightis about 7.0 mm, 10.0 mm, 11.0 mm, 12.0 mm, or 14.0 mm; and thetrapezoid wedge composite bone graft has a length of from about 15.0 mmto about 35.0 mm, preferably from about 17.0 mm to about 30.0 mm, morepreferably from about 20.0 mm to about 27.0 mm, and most preferably alength of about 21.0 mm, or 23.0 mm.

The bone portions may be interlocking and/or connected with one or moremechanical and/or chemical biocompatible connectors. The preferredconnectors include mechanical connectors including for example, one ormore cortical bone pins having a round cross-section and having adiameter of from about 1.0 mm to about 6.0 mm, preferably from about 2.0mm to about 5.0 mm, more preferably from about 2.0 mm to about 4.5 mm,and most preferably a pin diameter of from about 2.0 mm to about 4.0 mm,where the diameter of each pin in a single graft may be the same ordifferent. The diameter of the two corresponding through-holes ispreferably sufficient to provide an interference or frictional orslidable connection between the bone portions and the pin, preferably ainterference or frictional connection. The foregoing described trapezoidwedge composite optionally includes a cancellous bone portion disposedbetween the two cortical bone portions and having the same width or agreater width than the cortical bone portions. The trapezoid wedgecomposite graft can optionally include diametrically opposed chamferededges.

Most preferable trapezoid wedge composite bone grafts include thefollowing configurations:

-   -   (a) a first cortical portion having a width of from about 3.0 mm        to about 4.0 mm, preferably about 4.0 mm; a second cortical bone        portion having a width of from about 3.0 mm to about 4.0 mm,        preferably about 4.0 mm; a central cancellous bone portion        having a width of from about 3.0 mm to about 5.0 mm, preferably        about 3.0 mm disposed there between, forming a graft unit, the        graft unit held together by two round cortical bone pins having        a diameter of from about 2.0 mm to about 4.0 mm, the composite        graft having an overall length of about 21.0 mm, an anterior        height of about 9.0 mm, and a posterior height of about 11.0 mm;        or an anterior height of about 8.0 mm and a posterior height of        about 10.0 mm, or an anterior height of about 10.0 mm and a        posterior height of about 12.0 mm, or an anterior height of        about 12.0 mm and a posterior height of about 14.0 mm.    -   (b) a first cortical portion having a width of about 4.0 mm; a        second cortical bone portion having a width of about 4.0 mm; a        central cancellous bone portion having a width of about 3.0 mm        disposed there between forming a graft unit, the graft unit held        together by two round cortical bone pins having a diameter of        about 3.0 mm, the composite graft having an overall length of        about 21.0 mm, an anterior height of about 9.0 mm, and a        posterior height of about 11.0 mm, or an anterior height of        about 8.0 mm and a posterior height of about 10.0 mm, or an        anterior height of about 10.0 mm and a posterior height of about        12.0 mm, or an anterior height of about 12.0 mm and a posterior        height of about 14.0 mm; and where the length of the graft        measured from the posterior end to the center of the first pin        is about 5.5 mm, the length of the graft measured from the        center point of a first pin to a center point of a second pin is        about 8.0 mm and, the length of the graft measured from a center        point of a second pin to the anterior end of the graft is about        7.5 mm, and optionally having opposing textured surfaces where        the protrusions are in a saw-tooth pattern, and have a height of        about 1.2 mm and have an angle of about 60° between protrusions;    -   (c) a first cortical portion having a width of about 3.0 mm; a        second cortical bone portion having a width of about 3.0 mm; a        central cancellous bone portion having a width of about 3.0 mm        its disposed there between forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 4.0 mm, the composite graft having an overall length of        about 21.0 mm, an anterior height of about 7.0 mm, and a        posterior height of about 9.0 mm, or an anterior height of about        8.0 mm and a posterior height of about 10.0 mm, or an anterior        height of about 10.0 mm and a posterior height of about 12.0 mm,        or an anterior height of about 12.0 mm and a posterior height of        about 14.0 mm; and where the length of the graft measured from        the posterior end to the center of the first pin is about 6.0        mm, the length of the graft measured from the center point of a        first pin to a center point of a second pin is about 9.0 mm and,        the length of the graft measured from a center point of a second        pin to the anterior end of the graft is about 6.0 mm, and        optionally having opposing textured surfaces where the        protrusions are in a saw-tooth pattern, and have a height of        about 1.2 mm and have an angle of about 60° between protrusions;    -   (d) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 5.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 mm to about 4.0 mm, the composite graft having an        overall length of about 21.0 mm, an anterior height of about 9.0        mm, and a posterior height of about 11.0 mm;    -   (e) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 7.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 mm to about 4.0 mm, the composite graft having an        overall length of about 21.0 mm, an anterior height of about        11.0 mm, and a posterior height of about 13.0 mm;    -   (f) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 3.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 to about 4.0 mm, the composite graft having an        overall length of about 21.0 mm, an anterior height of about 7.0        mm, and a posterior height of about 9.0 mm;    -   (g) a first cortical portion having a width of about 4.0 mm, a        second cortical bone portion having a width of about 4.0 mm        forming a graft unit, the graft unit held together by two round        cortical bone pins having a diameter of about 3.0 mm, the        composite graft having an overall length of about 25.0 mm, an        anterior height of about 12.0 mm, and a posterior height of        about 15.0 mm;    -   (h) a first, second, third and fourth cortical bone portion each        having a width of from about 2.0 mm to about 3.0 mm, preferably        about 2.0 mm, a first cancellous bone portion having a width of        from about 2.0 mm to about 3.0 mm, preferably about 3.0 mm,        where the first cortical bone portion is disposed on the second        cortical bone portion, the first cancellous bone portion is        disposed between the second and third cortical bone portions,        and the fourth cortical bone portion is disposed on the third        cortical bone portion, forming a graft unit, the graft unit held        together by two round cortical bone pins having a diameter of        about 2.0 mm to about 4.0 mm, the composite graft having an        overall length of about 21.0 mm, an anterior height of about 9.0        mm, a posterior height of about 11.0 mm, and a composite width        of about 11.0 mm;    -   (i) a combination of at least two cortical bone portions        optionally having a cancellous bone portion disposed        therebetween, and having: (1) a posterior height of 9.0 mm an        anterior height of 7.0 mm, a length of 21.0 mm, and a composite        width of 12.0 mm; (2) a posterior height of 9.0 mm an anterior        height of 7.0 mm, a length of 25.0 mm, and a composite width of        12.0 mm; (3) a posterior height of 11.0 mm, an anterior height        of 9.0 mm, a length of 23.0 mm, and a composite width of 12.0        mm; (4) a posterior height of 11.0 mm, an anterior height of 9.0        mm, a length of 25.0 mm, and a composite width of 12.0 mm; (5) a        posterior height of 13.0 mm, an anterior height of 11.0 mm, a        length of 25.0 mm, and a composite width of 12.0 mm; and (6) a        posterior height of 15.0 mm, an anterior height of 13.0 mm, a        length of 25.0 mm, and a composite width of 12.0 mm; and    -   (j) a combination of two or more cortical bone portions        optionally each having a patterned surface such that an        interlocking fit between the bone portions is provided, and        having: (1) a posterior height of 14.0 mm an anterior height of        10.0 mm, a length of 21.0 mm, and a composite width of 7.0 mm,        two cortical bone pins each having a diameter of 3.0 mm, and a        slope of 10.8°, and having diametrically opposed chamfered edges        at 45° and 0.5 mm in depth, a distance from the center of the        first pin to the center point of the second pin of 8.0 mm, and a        distance from the anterior end of the graft to the center point        of the first pin of 7.5 mm; (2) a posterior height of 12.0 mm an        anterior height of 10.0 mm, a length of 21.0 mm, and a composite        width of 7.0 mm, two cortical bone pins each having a diameter        of 3.0 mm, and a slope of 5.45°, having diametrically opposed        chamfered edges at 45° and 0.5 mm in depth, a distance from the        center of the first pin to the second of the second pin of 80        mm, and a distance from the anterior end of the graft to the        center point of the first pin of 7.5 mm; (3) a posterior height        of 14.0 mm an anterior height of 12.0 mm, a length of 21.0 mm,        and a composite width of 7.0 mm, two cortical bone pins each        having a diameter of 3.0 mm, and a slope of 5.45°, having        diametrically opposed chamfered edges at 45° and 0.5 mm in        depth, a distance from the center of the first pin to the second        of the second pin of 8.0 mm, and a distance from the anterior        end of the graft to the center point of the first pin of 7.5        mm; (4) a posterior height of 11.0 mm, an anterior height of 9.0        mm, a length of 25.0 mm, and a composite width of 12.0 mm; (5) a        posterior height of 12.0 mm an anterior height of 9.8 mm, a        length of 23.0 mm, and a composite width of 7.0 mm, two cortical        bone pins each having a diameter of 3.0 mm, and a slope of 5.5°,        having diametrically opposed chamfered edges at 45° and 0.5 mm        in depth, a distance from the center point of the second pin to        the posterior end of the graft of 13.5 mm, and a distance from        the center point of the first pin to the posterior end of the        graft 5.5 mm; (6) a posterior height of 14.0 mm an anterior        height of 9.8 mm, a length of 23.0 mm, and a composite width of        7.0 mm, two cortical bone pins each having a diameter of 3.0 mm,        and a slope of 10.8°, having diametrically opposed chamfered        edges at 45° and 0.5 mm in depth, a distance from the center        point of the second pin to the posterior end of the graft of        13.5 mm, and a distance from the center point of the first pin        to the posterior end of the graft 5.5 mm; (7) a posterior height        of 13.0 mm an anterior height of 9.0 mm, a length of 23.0 mm,        and a composite width of 7.0 mm, two cortical bone pins each        having a diameter of 3.0 mm, and a slope of 10.8°, having        diametrically opposed chamfered edges at 45° and 0.5 mm in        depth, a distance from the center point of the second pin to the        posterior end of the graft of 13.5 mm, and a distance from the        center point of the first pin to the posterior end of the graft        of 5.5 mm; (8) a posterior height of 13.0 mm an anterior height        of 11.0 mm, a length of 23.0 mm, and a composite width of 7.0        mm, two cortical bone pins each having a diameter of 3.0 mm, and        a slope of 5.4°, having diametrically opposed chamfered edges at        45° and 0.5 mm in depth, a distance from the center point of the        second pin to the posterior end of the graft of 13.5 mm, and a        distance from the center point of the first pin to the posterior        end of the graft 5.5 mm; (9) a posterior height of 11.0 mm an        anterior height of 9.0 mm, a length of 23.0 mm, and a composite        width of 7.0 mm, two cortical bone pins each having a diameter        of 3.0 mm, and a slope of 5.4°, having diametrically opposed        chamfered edges at 45° and 0.5 mm in depth, a distance from the        center point of the second pin to the posterior end of the graft        of 13.5 mm, and a distance from the center point of the first        pin to the posterior end of the graft of 5.5 mm; (10) a        posterior height of 7.0 mm an anterior height of 5.0 mm, a        length of 21.0 mm, two cortical bone pins, and optionally having        diametrically opposed chamfered edges; (11) a posterior height        of 7.0 mm an anterior height of 5.0 mm, a length of 23.0 mm, two        cortical bone pins and optionally having diametrically opposed        chamfered edges; and (12) a posterior height of 7.0 mm an        anterior height of 5.0 mm, a length of 25.0 mm, two cortical        bone pins, and optionally having diametrically opposed chamfered        edges.

The composite bone grafts having a parallel block shape and optionallyhaving opposing textured surfaces disposed perpendicular to theinterfaces of the bone portions, and optionally having diametricallyopposed chamfered edges, preferably include: a combination of two ormore bone portions, preferably cortical bone portions, optionally eachhaving a patterned surface such that an interlocking fit betweenadjacent bone portions is provided; and: (a) at least two cortical boneportions each having a width offrom about 1.5 mm to about 10.0 mm,preferably from about 2.0 mm to about 7.0 mm, more preferably from about3.0 mm to about 5.0 mm, and most preferably having a width of about 4.0mm to give a composite width of about 15.0 mm; the parallel blockcomposite bone graft has a height from about 5.0 mm to about 20.0 mm,preferably from about 7.0 mm to about 19.0 mm, more preferably fromabout 8.0 mm to about 17.0 mm, and most preferably from about 9.0 mm toabout 16.0 mm; and the parallel block composite bone graft has a lengthof from about 15.0 mm to about 35.0 mm, preferably from about 17.0 mm toabout 30.0 mm, more preferably from about 20.0 mm to about 27.0 mm, andmost preferably a length of from about 21.0 mm to about 25.0 mm. Thepreferred mechanical connectors include one or more, preferably twocortical bone pins having a round cross-section and having a diameter offrom about 1.0 mm to about 6.0 mm, preferably from about 2.0 mm to about5.0 mm, more preferably from about 2.5 mm to about 4.5 mm, and mostpreferably a pin diameter of from about 3.0 mm to about 4.0 mm, wherethe diameter of each cortical bone pin may be the same of different. Thediameter of the two corresponding through-holes is preferably sufficientto provide an interference or frictional or slidable connection betweenthe bone portions and the pin, preferably a interference or frictionalconnection, and

-   -   (b) two or more cortical bone portions layered to form a graft        unit, and optionally one or more cancellous bone portions        disposed between said cortical bone portions, the graft unit        being connected by one or more mechanical connectors, preferably        two cortical bone pins having a diameter of from about 1.0 mm to        about 6.0 mm, preferably from about 2.0 mm to about 5.0 mm, more        preferably from about 2.5 mm to about 4.5 mm, and most        preferably a pin diameter of from about 3.0 mm to about 4.0mm,        where the diameter of each pin may be the same or different, and        having a composite width of from 4.5 mm to about 30.0 mm,        preferably from about 6.0 mm to about 21.0 mm, more preferably        from about 9.0 mm to about 15.0 mm, and most preferably having a        width of about 4.0 mm to give a composite width of about 12.0 mm        to about 15.0 mm, a posterior and anterior height of from about        5.0 mm to about 20.0 mm, preferably from about 9.0 mm to about        17.0 mm, and a length of from about 20.0 mm to about 30.0 mm,        specific preferred configurations include the following:        following configurations: (1) an anterior and posterior height        of about 9.0 mm, and a length of about 25.0 mm; (2) an anterior        and posterior height of about 9.0 mm, and a length of about 21.0        mm; (3) an anterior and posterior height of about 11.0 mm, and a        length of about 25.0 mm; (4) an anterior and posterior height of        about 11.0 mm, and a length of about 21.0 mm; (5) an anterior        and posterior height of about 13.0 mm, and a length of about        25.0 mm; (6) an anterior and posterior height of about 1.0 mm,        and a length of about 23.0 mm; (7) an anterior and posterior        height of about 13.0 mm, and a length of about 23.0 mm; (8) an        anterior and posterior height of about 15.0 mm, and a length of        about 25.0 mm; and (9) an anterior and posterior height of about        17.0 mm, and a length of about 25.0 mm. The foregoing described        parallel block composite bone graft optionally includes a        cancellous bone portion disposed between the two cortical bone        portions and having the same width or a greater width than the        cortical bone portions.

Most preferable parallel block composite bone grafts include thefollowing configurations: (a) two or more cortical bone portions havinga composite width of about 15.0 mm, held together by two round corticalbone pins having a diameter of about 2.0 mm to about 4.0 mm, where eachpin has the same or a different diameter, the composite graft having aheight of about 16.0 mm and a length of about 25.0 mm,

-   -   (b) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, one        or more central cancellous bone portions having a composite        width of about 9.0 mm disposed there between, forming a graft        unit, the graft unit held together by two round cortical bone        pins having a diameter of about 2.0 mm to about 4.0 mm, where        the diameter of each pin is the same or different, the composite        graft having a height of about 16.0 mm and an overall length of        about 25.0 mm, the parallel block composite bone graft also        includes opposing textured surfaces disposed perpendicular to        the interfaces of the bone portions;    -   (c) a first cortical bone portion having a width of about 3.0        mm, a second cortical bone portion having a width of about 3.0        mm, a central cancellous bone portion having a width of about        3.0 mm disposed there between, forming a graft unit, the graft        unit held together by two round cortical bone pins having a        diameter of about 2.0 mm to about 4.0 mm, where the diameter of        each bone pin is the same or different, the composite graft        having a height of about 10.0 mm and a length of about 25.0 mm,        the parallel block composite bone graft also includes opposing        textured surfaces disposed perpendicular to the interfaces of        the bone portions;    -   (d) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 3.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 mm to about 4.0 mm, where the diameter is the same        or different, the composite graft having a height of about 9.0        mm and a length of about 21.0 mm,    -   (e) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 5.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 mm to about 4.0 mm, Where the diameter of each bone        pin is the same or different, the composite graft having a        height of about 11.0 mm and a length of about 21.0 mm, and    -   (f) a first cortical portion having a width of about 3.0 mm, a        second cortical bone portion having a width of about 3.0 mm, a        central cancellous bone portion having a width of about 7.0 mm        disposed there between, forming a graft unit, the graft unit        held together by two round cortical bone pins having a diameter        of about 2.0 mm to about 4.0 mm, where the diameter of each bone        pin is the same or different, the composite graft having a        height of about 13.0 mm and a length of about 21.0 mm.

Most preferable cortical block composite bone grafts include thefollowing configurations: (a) a plurality of cortical bone portions eachhaving a width of from about 3.0 mm to about 4.0 mm, preferably about3.0 mm and the plurality of cortical bone portions having a compositewidth of from about 18.0 to about 22.0 mm, preferably a composite widthof about 20.0 mm, the cortical block composite has a height of fromabout 18.0 to about 22.0 mm, preferably of about 20.0 mm and a length offrom about 18.0 to about 22.0 mm, preferably of about 20.0 mm or 21.0mm, with the graft unit held together by two round cortical bone pinshaving a diameter of about 2.0 mm to about 4.0 mm, where the diameter ofeach pin is the same or different, and (b) the cortical block compositebone graft of (a) where one or more of the central cortical boneportions are replaced with one or more cancellous bone portions havingan overall width of from about 3.0 to about 15.0 mm, preferably about14.0 mm.

Most preferable cervical wedge grafts (flattened curved wedge compositebone grafts) for cervical fusion, include the following configurations:a combination of two or more cortical bone portions optionally eachhaving a patterned surface such that an interlocking fit between thebone portions is provided, and: (a) a first cervical (flattened curved)cortical portion having a width of from about 2.0 mm to about 8.0 mm; asecond cervical cortical bone portion having a width of from about 2.0mm to about 8.0 mm; where the first portion is disposed on the secondportion forming a graft unit, the graft unit is held together by atleast two cortical bone pins having a diameter of from about 2.0 mm toabout 4.0 mm, preferably 2.0 mm to about 3.0 mm; where the diameter ofeach pin is the same or different, the composite graft having a width ofabout 10.0 to about 20.0 mm, preferably about 16.0 mm, a diameter ofabout 10.0 mm to about 18.0 mm, preferably about 13.0 mm, and acentrally located hole, preferably from about 2.0 to about 8.0 mm indiameter, more preferably from about 3.0 to about 5.0 mm in diameter,disposed through the pinned graft unit, between at least two pins. Eachof the top and bottom surfaces of the cervical fusion graft, from a sideview, may be sloped at an angle of from about 0° to about 15°,preferably at an angle of from about 3° to about 10°, and mostpreferably one of the top or bottom surfaces sloped at an angle of about7° with the other surface not sloped, along the top and bottom faces ofthe graft from the curved top end to the flattened bottom end as shownin FIGS. 14 and 15, to form the wedge shape. The anterior compositewidth at the flattened end is preferably from about 6.0 to about 8.0 mm.The top and bottom opposing faces of the cervical graft may optionallybe textured, preferably with a plurality of pyrimidal protrusions,

-   -   (b) a first cervical (flattened curved) cortical portion having        a width of from about 2.0 mm to about 8.0 mm; a second cervical        cortical bone portion having a width of from about 2.0 mm to        about 8.0 mm; where the first portion is disposed on the second        portion forming a graft unit, the graft unit is held together by        at least two cortical bone pins having a diameter of from about        2.0 mm to about 4.0 mm, preferably 2.0 mm to about 3.0 mm; where        the diameter of each pin may be the same or different, the        composite graft having a width of about 15.0 to about 25.0 mm,        preferably about 19.0 mm, a diameter ofabout 12.0 mm to about        20.0 mm, preferably about 15.0 mm, and a centrally located hole        disposed through the pinned graft unit, between at least two        pins. The cervical fusion graft, from a side view, is preferably        sloped at an angle of from about 30 to about 15°, preferably at        an angle of about 7° along the top and bottom faces, or an angle        of 0° along the top surface and an angle of 7° along the bottom        surface, of the graft from the curved end to the flattened end        as shown in FIGS. 14 and 15, to form the wedge shape. The        anterior composite width at the flattened end is preferably from        about 6.0 to about 8.0 mm. The top and bottom opposing faces of        the cervical graft may optionally be textured, preferably with a        plurality of pyrimidal protrusions,    -   (c) a first and a second cervical (flattened curved) cortical        bone portion, the first bone portion disposed on the second bone        portion to form a graft unit, the graft unit is held together by        at least two cortical bone pins having a diameter of from about        2.0 mm to about 4.0 mm, and having the following preferred        configurations: a posterior composite width of from 5.0 mm to        15.0 mm, preferably from about 8.0 mm to 10.0 mm, an anterior        composite width of from about 5.0 mm to about 10.0 mm,        preferably from about 6.0 mm to about 8.0 mm,; the composite        graft having a width of from about 12.0 to about 25.0 mm,        preferably from about 16.0 mm to about 19.0 mm, a diameter of        from about 10.0 mm to about 20.0 mm, preferably from about 13.0        mm to about 15.0 mm, and a centrally located hole disposed        through the pinned graft unit, between at least two pins. The        graft, from a side view, is preferably sloped at an angle of        from about 3° to about 15°, preferably at an angle of about 7°,        or an angle of 0° along the top surface and an angle of 7° along        the bottom surface, along the top and bottom faces of the graft        from the curved end to the flattened end as shown in FIGS. 14        and 15, to form the wedge shape. The top and bottom opposing        faces of the cervical graft may optionally be textured,        preferably with a plurality of pyrimidal protrusions; and    -   (d) two or more bone portions preferably cortical bone portions,        layered to form a graft unit, where the bone portions are        connected by: being configured to interlock with each other        where the interlocking is self-locking or is locked with one or        more pins entirely or partially traversing a dimension of the        graft, and/or at least two cortical bone pins having a diameter        of from about 2.0 mm to about 4.0 mm and having the following        preferred configurations: (I) a diameter of about 14.0 mm; a        width of about 17.5 mm; a pin diameter of about 2.5 mm; a        through-hole having a diameter of about 6.5 mm, a first width of        about 9.0 mm, and a second width of about 4.0 mm; a distance        from the arc to a pin and from the through-hole to the second        width of the graft, of about 2.0 mm; a second width of about        10.0 mm, and the graft having its sides sloped at an angle of        about 25° (see FIG. 44); and (ii) a diameter of about 12.0 mm; a        width of about 14.5 mm; a pin diameter of about 2.5 mm; a        through-hole having a diameter of about 4.0 mm; a distance from        the arc to a pin and from the through-hole to the second width        of the graft, and from the pin to the through-hole, of about 2.0        mm; a second width of about 7.75 mm, and the graft having its        sides sloped at an angle of about 25° (see FIG. 43).

Most preferable anterior lumbar oval wedge composite bone grafts includethe following configurations: (a) two or more ovoid cortical boneportions disposed on each other thereby forming a graft unit having acomposite posterior width of from about 5.0 mm to about 20.0 mm,preferably from about 1.0 mm to about 15.0 mm, an anterior compositewidth of from 5.0 mm to about 20.0 mm, preferably from about 8.0 mm toabout 14.0 mm, a height of from about 15.0 mm to about 30.0 mm,preferably from about 21.0 mm to about 28.0 mm, and a length of fromabout 23.0 mm to about 45.0 mm, preferably from about 32.0 mm to about42.0 mm; the graft unit is held together by at least two cortical bonepins having a diameter of from about 2.0 mm to about 4.0 mm, where thepins have the same or a different diameter, to form a pinned graft unit;and optionally one or more through-holes disposed through the pinnedgraft unit. The graft, from a side view, is preferably sloped at anangle of from about 3° to about 15°, preferably at an angle of about 7°,or an angle of 0° along the top surface and an angle of 7° along thebottom surface, along the top and bottom faces of the to form the wedgeshape. The top and bottom opposing faces of the cervical graft mayoptionally be textured.

Any one or more of the cortical and/or cancellous bone portions of theabove-described composite bone grafts, may optionally be demineralizedand/or discontinuous, depending upon the particular clinicalapplication. For example, any one or more bone portions of any compositegraft may include for example, one or more horizontally disposedchannels, vertically disposed channels or randomly disposed channels,partially or completely traversing the height and/or width of the graft.One of ordinary skill in the art to which the present invention pertainscan readily select, make and employ, a particular composite graft,without undue experimentation.

V. Surgical Implantation and Indications

The present composite bone graft is useful for implantation in patientssuffering from defects caused by congenital anomaly, disease, or trauma,including for example, spine fractures; deformity, e.g. kyphoticdeformities, e.g. posttraumatic kyphosis; postlaminectomy kyphosis,junctional kyphosis, and Scheuermann's kyphosis; scoliosis, e.g.neuromuscular scoliosis, adult scoliosis, paralytic scoliosis,congenital and syndromic scoliosis; and cervical neck pain. Surgicalmethods for correcting degenerative conditions, for example in thelumbar spine, include decompression (excision of disc material,hypertrophied bone, or ligament along with fusion, or fusion alone.

A posterior surgical approach is preferably used. The choice of approachis dictated by the site of primary pathology and the physical size ofthe composite bone graft. Pathology that involves vertebral bodies isbest approached anteriorly through the thorax, abdomen or flank.Pathology involving posterior elements are best approached posteriorlyfor example, through a vertical midline approach or posterior lateralmuscle spinning approach.

Those of ordinary skill in the art to which the present inventionpertain, including for example an orthopaedic surgeon and a spinalsurgeon, can readily select and employ a particular composite bonegraft, without undue experimentation. Factors to be considered in suchselection and employment include: the type and size of graft bone, itsanatomic site of fusion, and the age of the patient. An ideal graft, forexample for use in lumbar interbody fusion, should be: osteoinductive,non-immunogenic, provide immediate mechanical stability, and beappropriately sized and shaped for the particular application/patient.Indications, diagnostic criteria, graft selection and surgicaltechnique, are factors that can be readily selected, optimized andemployed by those of ordinary skill in the art without undueexperimentation, and are discussed in: Master Techniques in OrthopaedicSurgery, The Spine, edited by Bradford, David S., Lippincott-Raven, ISBN0-7817-0033-7, Philadelphia, Pa., (1997), hereby incorporated herein byreference in its entirety. When implanting a cervical fusion graft, ananterior cervical approach is used.

The following examples are illustrative only, and do not in any waylimit the scope of the invention.

EXAMPLES I. Preparation of a Composite Graft

Donor bone was harvested according to industry accepted standards from acadaver donor. The composite bone grafts, sized as recorded in Table 1,were prepared according to the method described as follows. Using abandsaw cortical planks and pin segments were cut from a cortical shaft.One surface of each cortical planks was smoothed on a planing table andthe planks were cut to the recorded thickness using a mill. Thereafter,using a table saw, the cut planks were cut to the recorded width andlength. Cortical pins were then cut using a drill press, from the pinsegments. Using a drill sander, the cortical pins were taperedsufficient to allow insertion into the reamed graft unit. Next, using abandsaw, cancellous wafers were cut from cancellous bone to the recordedthickness. The wafers were then cut to the recorded width and lengthusing a table saw. The cortical planks and cancellous wafer were thenassembled into a graft unit in a jig and were then reamed using a drillpress. The anterior through-hole was disposed through the width of thegraft unit at the through-hole's center point, 7.5 mm along the lengthof the graft unit, and centered relative to the width of the graft unit.Using an arbor press, the cortical pins were pushed into the reamedgraft unit to produce a pinned graft unit. Any excess pin was then cutoff using a bandsaw. Next, using a drill sander, the pinned graft unitwas then shaped to the final recorded width, and if the composite graftwas angled, the pinned graft was then milled to cut angles. Thecomposite graft was milled to provide grooves of the recorded height, onthe opposing surfaces as shown in the Figures. The produced compositebone grafts were then cleaned and tested as follows.

TABLE 1 Composite Specimen Composite Tooth (mm) Height (mm) Length Pins(mm) Cancellous* Cortical* number Graft Type width (mm) Height anglefront back (mm) front back width (mm) width (mm) 1 trapezoid wedge (TA)9.0 1.2 60.0° 8.0 10.0 21.0 2.5 3.0 3.0 3.0 2 trapezoid wedge (TB) 11.01.5 60.0° 10.0 12.0 21.0 3.0 3.0 5.0 3.0 3 trapezoid wedge (TC) 13.0 1.560.0° 12.0 14.0 21.0 3.0 3.0 5.0 4.0 4 trapezoid wedge (TD) 13.0 1.560.0° 12.0 14.0 21.0 3.0 3.0 5.0  4.0** 5 parallel block (PA) 7.0 1.260.0° 9.0 9.0 21.0 2.5 2.5 3.0 2.0 6 parallel block (PB) 9.0 1.2 60.0°9.0 9.0 21.0 2.5 2.5 3.0 3.0 7 parallel block (PC) 9.0 1.2 60.0° 11.011.0 21.0 3.0 3.0 3.0 3.0 8 parallel block (PD) 9.0 1.2 60.0° 10.0 10.021.0 2.5 3.0 3.0 3.0 9 parallel block (PE) 11.0 1.5 60.0° 13.0 13.0 21.03.0 3.0 5.0 3.0 10 parallel block (PF) 11.0 1.5 60.0° 12.0 12.0 21.0 3.03.0 5.0 3.0 12 parallel block (PG) 13.0 1.5 60.0° 14.0 14.0 21.0 3.0 3.05.0  4.0** 11 parallel block (PH) 11.0 — — 9.0 9.0 21.0 3.0 3.0 5.0 3.012 parallel block (PI) 11.0 — — 9.0 9.0 21.0 3.0 3.0 3.0  4.0** 13parallel block (PJ) 9.0 — — 7.0 7.0 21.0 2.5 2.5 3.0 3.0 *+0.500 mm or−0.250 mm **two (2) cortical planks were used, each ˜2.0 mm to give acomposite cortical width of 4.0 mm

II. Biomechanical Strength

The biomechanical strength of the composite bone grafts recorded inTable 2 was determined using static compression testing. All of thetested bone grafts were produced as set forth in Example 1, and size asrecorded. All of the composite bone grafts were constructed from twocortical layers sandwiching a cancellous layer with all of the layersoriented parallel to the sagittal plane, and secured together with twocortical bone pins. Tests were performed under a compressive load usingan Instrom™ 4204 test machine. An axial displacement was applied in aramp fashion at 2.5 mm/min rate until catastrophic failure of the bonegraft occurred or until the maximum displacement of 3 mm was reached.Data collected at a rate of 2 Hz.

As can be seen from the data set forth in Table 2, all of the compositegrafts exhibited adequate to exceptional biomechanical strength, ascompared to the vertebral body itself which fails at 10,000 N (2,200lbs).

TABLE 2 Load at Displacement Load at Displacement Stiffness (slope)Graft Specimen Max. Load at Max. Load z-slp, yield at z-slp, yield(AutYoung) Type number (KN) (Mm) (Mm) (Mm) (N/mm) PA PA-1 8.464 3.4606.719 1.706 6708.0 (Donor 1) PA-2 8.923 2.450 8.625 1.957 6544.0 PA-38.569 3.020 7.323 1.851 6201.0 PA-4 7.238 3.070 6.727 1.998 4756.0 PA-58.395 2.160 8.078 1.873 7321.0 Mean (Donor 1): 8.318 2.832 7.495 1.8776306 Std. Dev (Donor 1): .637 .521 .842 .113 957 (Donor 2) PA-6 9.7183.300 6.636 1.560 5637.0 PA-7 8.118 1.970 8.113 1.956 6379.0 PA-8 11.1903.150 9.052 2.102 6246.0 PA-9 8.201 2.110 8.193 2.102 6643.0 PA-10 5.9921.430 5.882 1.248 7973.0 PA-11 7.248 2.500 7.130 2.060 6578.0 PA-128.319 2.660 8.228 2.123 6500.0 PA-13 6.325 2.690 5.782 1.624 4518.0PA-14 7.973 1.770 7.970 1.749 5867.0 PA-15 8.969 2.750 — — 5546.0 Mean(Donor 2): 8.205 2.433 — — 6189.0 Std. Dev. (Donor 2): 1.535 .601 — —900.0 (Donor 3) PA-16 7.259 1.540 7.256 1.541 8207.0 (Donor 4) PA-179.799 1.710 9.799 1.687 9930.0 PA-18 7.879 1.640 7.876 1.623 7963.0PA-19 9.590 1.620 9.584 1.603 9794.0 PA-20 9.388 1.670 9.380 1.6658773.0 PA-21 9.617 1.750 9.617 1.748 10260.0 Mean (Donor 4): 9.255 1.6789.251 1.655 9344.0 Std. Dev. (Donor 4) .783 .053 .783 .057 950 PC PC-19.165 4.000 7.216 1.811 10230.0 (Donor 5) PC-2 7.664 2.860 7.664 2.8534291.0 PC-3 8.360 2.810 8.338 2.791 4226.0 PC-4 8.612 .970 8.607 .95819260.0 Mean (Donor 5): 8.450 2.660 7.956 2.103 9503.0 Std. Dev. (Donor5): .623 1.254 .633 .900 7090.0 (Donor 6) PC-5 10.45 2.040 10.36 1.5409482.0 PC-6 10.17 2.140 10.17 2.144 7261.0 PC-7 11.74 2.090 11.73 2.06010330.0 PC-8 11.77 2.290 11.76 2.290 9123.0 Mean (Donor 6): 11.03 2.14011.01 2.009 9049.0 Std. Dev. (Donor 6): .84 .108 .86 .326 1295.0 PB PB-18.953 1.540 8.604 1.310 10160.0 (Donor 7) PB-2 10.910 1.850 10.910 1.85210380.0 Mean (Donor 7): 9.931 1.695 9.758 1.581 10270.0 Std. Dev. (Donor7): 1.336 .219 1.632 .383 156.0 PE PE-1 11.42 1.810 11.21 1.601 13900.0(Donor 8)

III Comparative Biomechanical Strength

Composite bone grafts were produced as described in Example A. 11×9×21mm grafts: (PH) having two 3.0 mm cortical layers sandwiching a 5.0 mmcancellous layer, and (PI) having two 4.0 mm cortical layers sandwichinga 3.0 mm cancellous layer; and 9×7×21 mm grafts (PJ) having two 3.0 mmcortical layers sandwiching a 3.0 mm cancellous layer, were produced.After production, the grafts were either fresh frozen or freeze-dried.Table 3 summarizes the compression test results of fresh frozencomposite grafts after thawing in 9.0% saline solution for 90 minutesand the freeze-dried composite bone grafts after soaking for 20 min., 60min., and 7 days in 9.0% saline solution.

Test results showed that the 20 minute soaked freeze-dried grafts hadthe highest strength (Table 3) and stiffness (Table 4) among all thetested groups. Generally, strength and stiffness of the fresh-frozengrafts were relatively lower than the freeze-dried grafts.

The inventive composite bone graft, both fresh-frozen and freeze-dried,when compared to commercially available bone graft products (Os™ and MidAmerica) was significantly stronger. See Brantigan et al, CompressionStrength of Donor Bone for Posterior Lumbar Interbody Fusion, Spine Vol.18, No. 9, 1993.

TABLE 3 Specimen Number Graft Type 1 2 3 4 5 Mean Std. Dev. FreshFrozen-one-hour (PH-1) 9.114 9.160 6.942 6.945 9.852 8.403 1.364 FreshFrozen-one-hour (PH-2) 9.176 8.744 — — — 8.960 0.305 Freeze-dried-20.0min. (PI-1) 13.970 14.460 — — — 14.220 0.346 Freeze-dried-one-hour(PI-2) 13.99 13.97 — — — 13.98 0.014 Freeze-dried-seven-days (PI-3)10.300 8.255 — — — 9.277 1.446 Fresh Frozen-one-hour (PJ-1) 7.925 7.9738.958 7.836 9.799 8.498 .985 Fresh Frozen-one-hour (PJ-2) 8.897 9.015 —— — 8.956 .083 Os ™* 1.098 .934 5.72 2.145 — 2.474 2.229 Mid AmericaTricortical** 2.823 1.699 1.926 2.629 2.464 2.308 0.477 *Os ™ bone is acommercial tricortical bone graft product. **Mid America tricortical isa commercially available bone graft product produced by Mid America.

TABLE 4 Specimen Number Graft Type 1 2 3 4 5 Mean Std. Dev. FreshFrozen-one-hour 7053.0 6176.0 5878.0 5434.0 7528.0 6413.8 1103.4 (PJ-1)(9 × 7, 3-3-3) Fresh Frozen-one-hour 7303.0 6112.0 — — — 6707.5 842.2(PJ-2) (9 × 7, 3.3-3) Fresh Frozen-one-hour 10980.0 13900.0 — — —12440.0 2064.8 (PH-1) (11 × 9, 3-5-3) Fresh Frozen-one-hour 4938.011340.0 11060.0 12180.0 9125.0 9728.0 2902.3 (PH-2) (11 × 9, 3-5-3)Freeze-dried-20.0 min. 27760.0 28420.0 — — — 28090.0 466.7 (PI-1) (11 ×9, 4-3-4) Freeze-dried-one-hour 21940.0 22890.0 — — — 22415.0 671.8(PI-2) (11 × 9, 4-3-4) Freeze-dried-seven-days 14590.0 18130.0 — — —16360.0 2503.2 (PI-3) (11 × 9, 4-3-4)

IV. Preparation of a Cervical Wedge Composite Graft

Donor bone was harvested according to industry accepted standards from acadaver donor. The composite bone grafts, sized as recorded in Table 5,were prepared according to the method described as follows. Using abandsaw cortical planks and pin segments were cut from a cortical shaft.One surface of each cortical planks was smoothed on a planing table andthe planks were cut to the required thickness using a mill. Thereafter,using a table saw, the cut planks were cut to the required width andlength. Cortical pins were then cut using a drill press, from the pinsegments. Using a drill sander, the cortical pins were taperedsufficient to allow insertion into the reamed graft unit. Next, thecortical planks were assembled into a graft unit in a jig and were thenreamed using a drill press. Using an arbor press, the cortical pins werepushed into the reamed graft unit to produce a pinned unit. At thispoint, the pinned unit was optionally sloped at it's top and/or bottomsurface, for example at its bottom surface, at 7° using a radial saw. Acircular shape was then cut through the pinned and optionally slopedunit using a trephine or Cloward cutter of appropriate size. Thereafter,using a radial saw or a band saw, the sides and bottom of the graft wereshaped, and a centrally located hole was drilled through the pinnedunit. Any excess pin was then cut off using a bandsaw. Lastly, thepinned graft unit was smoothed. If textured, the composite graft wasmilled to provide grooves on the opposing surfaces as shown in FIG. 35.

TABLE 5 Composite Specimen Width (mm) Diameter Width number Graft TypeFront back (Mm) (Mm) 1. Cervical Wedge (CA) 6.0 10.0 13.0 16.0 2.Cervical Wedge (CB) 7.0 11.0 13.0 16.0 3. Cervical Wedge (CC) 8.0 12.013.0 16.0 4. Cervical Wedge (CD) 6.0 10.0 15.0 19.0 5. Cervical Wedge(CE) 7.0 11.0 15.0 19.0 6. Cervical Wedge (CF) 8.0 12.0 15.0 19.0 7.Cervical Wedge (CG) 6.0 6.0 13.0 16.0 8. Cervical Wedge (CH) 8.0 8.013.0 16.0 9. Cervical Wedge (CI) 6.0 6.0 15.0 19.0 10. Cervical Wedge(CJ) 7.0 7.0 13.0 16.0 11. Cervical Wedge (CK) 7.0 7.0 15.0 19.0

It is to be understood, however, that the scope of the present inventionis not to be limited to the specific embodiments described above. Theinvention may be practiced other than as particularly described andstill be within the scope of the accompanying claims.

1. A composite bone graft, consisting essentially of: two or moredistinct, adjacent, cortical bone portions, said distinct, adjacent,cortical bone portions each comprising a face complimentary to a face onan adjacent cortical bone portion, each face comprising a singleprojection or a single depression, such that adjacent faces arecomplimentary, and a single projection interlocks with a singledepression, to provide an interlocking fit between said adjacent boneportions; and one or more locking pins comprising cortical bone,partially or entirely traversing a dimension of said composite bonegraft, said one or more locking pins provided perpendicular to orparallel to an interface between adjacent bone portions, said corticalbone portions are not demineralized.
 2. A composite bone graft,comprising: two or more distinct, adjacent, cortical bone portions, saiddistinct, adjacent, cortical bone portions each comprising a facecomplimentary to a face on an adjacent cortical bone portion, each facecomprising a single projection or a single depression, such thatadjacent faces are complimentary, and a single projection interlockswith a single depression, to provide an interlocking fit between saidadjacent bone portions; and one or more locking pins comprising corticalbone, partially or entirely traversing a dimension of said compositebone graft, said one or more locking pins provided perpendicular to orparallel to an interface between adjacent bone portions, wherein saidcomposite bone graft does not comprise an adhesive, said cortical boneportions are not demineralized.
 3. A composite bone graft comprising twoor more distinct, adjacent, cortical bone portions layered to form agraft unit; one or more bone pins provided perpendicular to an interfacebetween adjacent bone portions; and a first chamfered edge and a secondchamfered edge, said first chamfered edge provided along a length ofsaid composite bone graft at its top edge, and said second chamferededge provided along a length of said composite bone graft at its bottomedge, such that the chamfered edges are diametrically opposed, whereinsaid composite bone graft does not comprise an adhesive, said corticalbone portions are not demineralized.
 4. A composite bone graft,comprising: two or more distinct, adjacent, cortical bone portions, saiddistinct, adjacent, cortical bone portions each comprising a facecomplimentary to a face on an adjacent cortical bone portion, each facecomprising a single projection or a single depression, such thatadjacent faces are complimentary, and a single projection interlockswith a single depression, to provide an interlocking fit between saidadjacent bone portions, wherein said composite bone graft does notcomprise an adhesive and said cortical bone portions are notdemineralized and not bonded to each other through chemical linkages. 5.The composite bone graft of claim 4, further comprising one or more bonepins.
 6. The composite bone graft of claim 5, one or more bone pinscomprise one or more cortical bone pins, said bone pins are notdemineralized.
 7. The composite bone graft of claim 6, said one or morecortical bone pins are located perpendicular to interfaces of adjacentbone portions, and entirely traverse said composite bone graft.
 8. Thecomposite bone graft of claim 6, said one or more cortical bone pinscomprise locking pins located parallel to interfaces of adjacent boneportions, where one locking pin is provided at each interface ofadjacent bone portions parallel to that interface, said locking pinspartially traverse said composite bone graft.
 9. A composite bone graft,comprising: a first substantially planer cortical bone portion; a secondsubstantially planer cortical bone portion provided on said firstsubstantially planer cortical bone portion to form a graft unit; and oneor more bone pins for holding together said graft unit, said one or morebone pins are provided perpendicular to or parallel to an interface ofsaid first substantially planer cortical bone portion and said secondsubstantially planer cortical bone portion, wherein said composite bonegraft does not comprise an adhesive, said cortical bone portions are notdemineralized.
 10. The composite bone graft of claim 9, said compositebone graft is a composite cervical wedge, said composite cervical wedgecomprising: a top textured surface; a bottom textured surface; a firstwidth of from about 10.0 mm to about 24.0 mm; a second width of fromabout 4.0 mm to about 16.0 mm; a composite anterior height of from about3.0 mm to about 30.0 mm; a composite posterior height of from about 5.0mm to about 50.0 mm; and a length of from about 10.0 mm to about 20.0mm, wherein said top textured surface and said bottom textured surfaceare opposing, said top textured surface and said bottom textured surfacecomprises a plurality of continuous linear protrusions defining asaw-tooth pattern.
 11. The composite bone graft of claim 9, saidcomposite bone graft is a composite cervical block, said compositecervical block comprising: a top textured surface; a bottom texturedsurface; a first width of from about 10.0 mm to about 24.0 mm; a secondwidth of from about 4.0 mm to about 16.0 mm; a composite height of fromabout 3.0 mm to about 30.0 mm; and a length of from about 10.0 mm toabout 20.0 mm, wherein said top textured surface and said bottomtextured surface are opposing, said top textured surface and said bottomtextured surface comprises a plurality of continuous linear protrusionsdefining a saw-tooth pattern.
 12. A composite bone graft, consistingessentially of: a first substantially planer cortical bone portion; asecond substantially planer cortical bone portion provided on said firstsubstantially planer cortical bone portion to form a graft unit; and oneor more bone pins for holding together said graft unit, said one or morebone pins are provided perpendicular to or parallel to an interface ofsaid first substantially planer cortical bone portion and said secondsubstantially planer cortical bone portion, said cortical bone portionsare not demineralized.
 13. The composite bone graft of any one of claims9 or 12, said first substantially planer cortical bone portion comprisesone or more cortical bone planks, and said second substantially planercortical bone portion comprises one or more cortical bone planks. 14.The composite bone graft of claims 13, said composite bone graft furthercomprising a first top surface and a second bottom surface, said firsttop surface and said second bottom surface comprising a plurality ofcontinuous linear protrusions defining a saw-tooth pattern.
 15. Thecomposite bone graft of any one of claims 14, 10, or 11, said continuouslinear protrusions comprise a height of from about 0.1 mm to about 5.0mm.
 16. The composite bone graft of any one of claims 9 or 12, saidcomposite bone graft is a composite trapezoid wedge, said compositetrapezoid wedge, comprising: a top textured surface; a bottom texturedsurface; an anterior height of from about 3.0 mm to about 30.0 mm; aposterior height of from about 5.0 mm to about 50.0 mm; a compositewidth of from about 4.0 mm to about 20.0 mm; and a length of from about5.0 mm to about 50.0 mm, wherein said top textured surface and saidbottom textured surface are opposing and are disposed perpendicular tointerfaces of said bone portions, said top textured surface and saidbottom textured surface comprises a plurality of continuous linearprotrusions defining a saw-tooth pattern.
 17. The composite bone graftof claim 16, said plurality of continuous protrusions having a height offrom about 0.1 mm to about 5.0 mm.
 18. The composite bone graft of anyone of claims 9 or 12, said bone portions comprise allogenic orxenogenic bone.
 19. The composite bone graft of any one of claims 9 or10, said composite bone graft is a composite parallel block, saidcomposite parallel block comprising: a top textured surface; a bottomtextured surface; a height of from about 3.0 mm to about 30.0 mm; acomposite width of from about 4.0 mm to about 20.0 mm; and a length offrom about 5.0 mm to about 50.0 mm, wherein said top textured surfaceand said bottom textured surface are opposing and are disposedperpendicular to interfaces of said bone portions, said top texturedsurface and said bottom textured surface comprises a plurality ofcontinuous linear protrusions defining a saw-tooth pattern.
 20. Thecomposite bone graft of any one of claims 19 or 11, further comprising athrough-hole entirely traversing said composite bone graft and disposedsubstantially perpendicular to interfaces of said bone portions.
 21. Thecomposite bone graft of claim 20, said through-hole comprising across-section having a shape selected from the group consisting of:substantially round; substantially elliptical; and substantially oval.22. The composite bone graft of claim 19, said plurality of continuousprotrusions having a height of from about 0.1 mm to about 5.0 mm.
 23. Acomposite bone graft, comprising: a first cortical bone portion; asecond cortical bone portion provided on said first cortical boneportion to form a graft unit; and one or more bone pins for holdingtogether said graft unit, said one or more bone pins are providedperpendicular to or parallel to an interface of said first cortical boneportion and said second cortical bone portion, wherein said compositebone graft does not comprise an adhesive and said cortical bone portionsare not demineralized.
 24. The composite bone graft of claim 23, saidfirst cortical bone portion comprises one or more cortical bone planks,and said second cortical bone portion comprises one or more corticalbone planks.
 25. The composite bone graft of claim 24, said firstcortical bone portion comprises a first face comprising a singleprotrusion and said second cortical bone portion comprises a second facecomprising a single depression complimentary to said first face, suchthat said first face and said second face interlock.
 26. The compositebone graft of any one of claims 9-3, 23-24, or 25, said composite bonegraft further comprising a first top surface and a second bottomsurface, said first top surface and said second bottom servicecomprising a plurality of continuous linear protrusions defining asaw-tooth pattern.
 27. The composite bone graft of claim 26, saidplurality of continuous protrusions having a height of from about 0.1 mmto about 5.0 mm.
 28. The composite bone graft of any one of claims 9-3,or 23, said composite bone graft further comprising a top surface; abottom surface; a diameter of from about 10.0 mm to about 20.0 mm; awidth of from about 12.0 mm to about 25.0 mm; an anterior compositeheight of from about 5.0 mm to about 10.0 mm; and a posterior compositeheight of from about 5.0 mm to about 15.0 mm.
 29. The composite bonegraft of claim 28, said top surface and said bottom surface comprising aplurality of continuous linear protrusions defining a saw-tooth pattern.30. The composite bone graft of claim 29, said plurality of continuousprotrusions having a height of from about 0.1 mm to about 5.0 mm.